Studies have suggusted that twins, in their early years, tend to have lower IQs and pick up language more slowly than non-twins. The slower intellectual growth may be caused by benign parental neglect. Suppose it is desired to estimate the mean attention time given
to twins per week by their parents. A sample of 26 sets of two-year-old twin boys was taken, and after one week the attention time
received was recorded. The mean was found to be 27.4 hours with a standard deviation of 11,2 hours. Use this information to contruc
a 98% confidence interval for the mean attention time given to all twin boys by their parents, assuming that the population is
approximately normally distributed, Round the endpoints to one decimal place.
Confidence interval:( , )

Answers

Answer 1

Answer:

Confidence interval: (21.9, 32.9).

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 26 - 1 = 25

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 25 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.98}{2} = 0.99[/tex]. So we have T = 2.485

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.485\frac{11.2}{\sqrt{26}} = 5.5[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 27.4 - 5.5 = 21.9 hours

The upper end of the interval is the sample mean added to M. So it is 27.4 + 5.5 = 32.9 hours

Confidence interval: (21.9, 32.9).


Related Questions

A bag contains 8 red marbles and 4 blue marbles. You randomly pick a marble and then pick a second marble without returning the first marble to the bag. What is the probability that both marbles are red?

Answers

Answer:

0.50%

Step-by-step explanation:

10. Find the measure of angle x.
11. Find the measure of angle ?

Answers

9514 1404 393

Answer:

  10. 28°

  11. 65°

Step-by-step explanation:

10. The two angles are complementary, so the unknown angle is ...

  x = 90° -62° = 28°

__

11. The three angles total 180°, so the unknown angle is ...

  ? = 180° -55° -60° = 65°

Meiling and Jackie are playing a game of chance with a six-sided number cube. The sides of the cube are numbered 1 to 6. Meiling scores a point each time she rolls a number greater than 4.​


Answers

Answer:

D. Jackie rolls a number that is less than 3.

Step-by-step explanation:

Every time Meiling rolls a number greater than a four, she will get a point. This gives her two numbers that she can get a point off of, 5 and 6. So If Jackie were to roll a number less than a three, Jackie would also get two numbers that she can get a point off of, 1 and 2. So the answer "Jackie rolls a number that is less than 3" will give Jackie an equally likely chance for a point.

Seven cards are drawn from an ordinary deck. In how many ways is it possible to draw ​(b) only 8​'s, ​'s and ​(c) no ​'s, ​'s and ​(d) exactly 2 or ​; ​(e) spades and ​hearts? ​(a) Number of ways to draw only ​'s ​= 0 ​(b) Number of ways to draw only ​'s, ​'s, and ​'s ​= 924 ​(c) Number of ways to draw no ​'s, ​'s, and ​'s ​= 3838380 ​(d) Number of ways to draw exactly 2 s or s ​= 3,801,028 ​(e) Number of ways to draw spades and hearts​ = 55770 Question is complete. Tap on the red indicators to see incorrect answers.

Answers

Complete question :

Seven cards are drawn from an ordinary deck. In how mnat ways is it possible to draw (a) only 5s (b)only 8s, 9s, and 10s, (c) no 8s, 9s, and 10s (d) exactly 2 jacks or kings, (e) 5 spades and 2 hearts?

Answer:

0; 792 ; 100396 ; 30408224 ; 18643560 ;

Step-by-step explanation:

Number of cards in a deck = 52

Number of cards to be drawn = 7

Using combination:

nCr = n! ÷ (n-r)!r!

A.)

Number of 5's in a deck = 4

4C7 = 0

(B.)

only 8s, 9s, and 10s,

Number of 8, 9 and 10's = 4 *3 = 12

12C7 = 12! ÷ 5!7! = 792

(C)

no 8s, 9s, and 10s ;

Number of cards to select from = 52 - (3(4)) = 40C7 = 18643560

(D)

exactly 2 jacks or kings,

Number of jack or king in deck = 8 ; other 5 could be any of the rest : (52 - 8) = 44

8C2 * 44C5 = 28 * 1086008 = 30408224

(e) 5 spades and 2 hearts?

Number of spades = 13

Number of hearts = 13

13C5 * 13C2

1287 * 78 = 100396

please help me with this as soon as you can

Answers

9514 1404 393

Answer:

  14.14

Step-by-step explanation:

The diagonal of a square is √2 times the side length.

  AC = AB×√2

  AC = 10√2 ≈ 14.14

_____

The diagonal of a square is the hypotenuse of an isosceles right triangle. If the sides of that are s and the diagonal is d, the Pythagorean theorem tells us ...

  d² = s² + s²

  d² = 2s²

  d = (√2)(√s²) = s√2

This relation holds for any isosceles right triangle, not just for the diagonal of this square. It is useful to remember.

The volume of a fish tank is 70 cubic feet. If the density is 0.4 fish over feet cubed, how many fish are in the tank?

175
88
28
14

Answers

Answer:

28 fish is the correct answer

Step-by-step explanation:.

The number of fish in the fish tank will be 28.

What is a volume?

Volume is defined as the space occupied by any object in the three-Dimensions. All three parameters are required for the volume like length, width, and height of the Cuboid.

The density of the fish is defined as the number of fish per unit volume of the tank.

Given that volume of a fish tank is 70 cubic feet and the density is 0.4 fish over feet cubed.

The number of fish is calculated as below:-

Number = Volume of tank x Density of fish

Number = 70 x 0.4

Number = 28 fish

Therefore, the number of fish in the fish tank will be 28.

To know more about volume follow

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2.6 cm = .........................mm

Answers

Answer:

26 mm

Step-by-step explanation:

1 cm is equal to 10 mm

2.6 cm

> 2.6 x 10

> 26 mm

helpppp meeee! pleaseeee!​

Answers

Answer:

9

11

17

25

Step-by-step explanation:

Input the x into the equation

Answer:

2×2+5=9

2×3+5=11

2×6+5=17

2×10+5=25

Solve for x.
7(x + 2) = 6(x + 5)
X=-44
x = -16
x = 16
X= 44
Look in picture
Help please

Answers

Answer:

x= 16

Step-by-step explanation:

First, you want to distribute each side! (you're gonna wanna learn this because you will be having to do it for the next 3 years no joke it sucks)

7(x+2) can be distributed as 7x+14 after multiplying 7 times x and 7 times 2, and 6(x+5) can be distributed as 6x+30.

Now, you have to get the x on one side to solve for x (so like x=__).

To do this, look at the equation as of now. 7x+14=6x+30.

We can minus 14 and bring that to the right, and minus 6x and bring that to the left to separate the x's and the regular numbers.

Now we have  16=x (or x=16).

5,000 is invested at an interest rate of 8% compounded annually. how much is the investment return after 20 years?​

Answers

Step-by-step explanation:

5k×8×20

_______ =800

100

Answer:

≈ 23305

Step-by-step explanation:

The amount A is calculated as

A = P [tex](1+r)^{t}[/tex]

P is the principal

r is the interest rate

t is the time in years

A = 5000 [tex](1+0.08)^{20}[/tex]

   = 5000 [tex](1.08)^{20}[/tex]

   ≈ 23305 ( to the nearest whole number )

The sides of a triangle have lengths 6, 8, and 11. What is
the length of the longest side of a similar triangle whose
perimeter is 75?

Answers

Answer:

48 is the answer

Step-by-step explanation:

The longest side of the similar triangle whose perimeter is 75 is 33 units.

What is a triangle?

A triangle is a geometric figure with three edges, three angles and three vertices. It is a basic figure in geometry.

The sum of the angles of a triangle is always 180°

The sides of the given triangle are,

6 units, 8 units and 11 units.

Also given that,

There is a similar triangle whose perimeter is 75 units.

To find the longest side of the similar triangle,

Let the sides of the similar triangle are 6x, 8x and 11x

The perimeter of triangle = 75

Implies that,

6x + 8x + 11x = 75

25 x = 75

x = 3

Since, the longest side of the similar triangle = 11 x

Substitute x = 3 here,

Longest side = 11 × 3 = 33 units

The required side of similar triangle is 33 units.

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Given vectors A=(1i+7j−2k)N and B=(−1i−10j+13k)N, find the magnitude of resultant of these two vectors and angle that the resultant of these two vector makes with the z axis.
IRI= ____ N,
γ=_____ °. pls help mangota​

Answers

Answer:

Step-by-step explanation:

y= 7.2

Iri=21.1

Answer:

that should be correct:)

Step-by-step explanation:

y= 7.2

Iri=21.1

answer and show Actual PROOF and ill give brainliest

Answers

Answer:

105m^3

Step-by-step explanation:

The volume of a rectangular prism is calculated by multiplying l*w*h. Basically, just multiply all the numbers together.

So that would be 3*5*7

Given f x please help me

Answers

Try math-way, it gives you the answers to stuff in mathematics, in this case algebra. Also there's no - between the two words, I had to do this because of brainly.

-9/5+-2/3+1/5+3/5 please solve someone

Answers

Answer:

-5/3

Step-by-step explanation:

-9/5 + -2/3 + 1/5 + 3/5

= (-9/5 + 1/5 +3/5) - 2/3 (combine the like terms)

= -1 - 2/3

= -5/3

Find mZDOC.
A)
22°
B)
44°
C)
107
D)
126

Answers

Answer: [tex]107^{\circ}[/tex]

Step-by-step explanation:

[tex]m\angle DOC=\frac{170+44}{2}=\boxed{107^{\circ}}[/tex]

Before starting to play the roulette in a casino you want to look for biases that you can exploit. Youtherefore watch 100 rounds that result in a number between 1 and 36 and you count the number ofrounds for which the result is odd. If the count exceeds 55, you decide that the roulette is not fair.Assuming that the roulette is fair, find an approximation for the probability that you will makethe wrong decision.

Answers

Answer:

[tex]P(n>55)=0.1357[/tex]

Step-by-step explanation:

From the question we are told that:

Sample size n=100

Sample space n'=36

Generally the equation for the mean number of times odds appears is mathematically given by

[tex]\=x_o=hp[/tex]

[tex]\=x_o=100*0.5[/tex]

[tex]\=x_o=50[/tex]

Generally the equation for standard deviation is mathematically given by

[tex]\sigma=(hp(1-p))^{1/2}\\\sigma=(50(0.5))^{1/2}[/tex]

[tex]\sigma=5[/tex]

Therefore probability to make wrong decision P(n>55)

[tex]P(n>55)=1-P(z<50.5/5)\\P(n>55)=1-P(z<1.1)\\P(n>55)=1-0.86[/tex]

[tex]P(n>55)=0.1357[/tex]

An approximation for the probability that you will make the wrong decision is 0.1587.

Probability

S=Number of time that the result was odd

n=100

p=0.5

Hence:

E[S]=100×0.5

E[S]=50

Standard deviation=√100×0.5×0.5

Standard deviation√25

Standard deviation=5

Using normal approximation to the binomial

P(S≥55)=P(S-50/5 ≥ 55-50/5)

P(S≥55)=1-P(z ≤ 1)

P(S≥55)=1-0.8413

P(S≥55)= 0.1587

Inconclusion  an approximation for the probability that you will make the wrong decision is 0.1587.

Learn more about probability here:https://brainly.com/question/24756209

What is 57 divided by 90?

Answers

Answer:

0.63 should be your answer

Answer;

0.6333333

Step-by-step explanation:

I think it's helps you

Brainliest for correct answer asap

Answers

Answer:

its the first one. Times the bigger numbers and add the indices. so it 16^7

Answer: A 16(7)

Step-by-step explanation:

First you multiply your base numbers,[4x4] to get 16 then you add your exponents [2+5] to get 7 and remember you can only add exponents not multiply them.

This sign is 50 centimeters high and 40 centimeters along the base. What is it’s area?

Answers

height =50

base=40

area of triangle =1/2b*h

1/2*40*50

1000

Please help me and no links or sites! Please

Answers

Answer:

B

Step-by-step explanation:

By using the fraction strip, if you think about it:

Pretend to color in 5/6 on the yellow side, and do the same to the 1/12 part, instead pretend to shade in 5/12. If you see how much remaining you have, you get 5/12.

PLEASE PLEASE HELP

find the value of y

Answers

Answer:

Step-by-step explanation:

y=108/2=54°

Answer:

Y = 54

Step-by-step explanation:

A cubical tank of edge 12 cm is half filled with water. The water is poured into an empty rectangular tank measuring 10 cm by 8 cm by 7 cm until it is full. How much water is left in the cubical tank? Give your answer in millilitres.

Answers

Answer:

3040000mm³

Step-by-step explanation:

Volume of a cube = a³ ; a = size of edge

Volume of cubical tank = 12³ = 12 * 12 * 12 = 1728 cm³

Half filled cube = 1728 / 2 = 864 cm³

Volume is f rectangular tank :

V = length * width * height

V = 10 * 8 * 7 = 560 cm³

Volume of water left in cubical tank :

(864 - 560) = 304cm³

1cm³ = 1000mm³

304cm³ = 304 * 1000 = 3040000mm³

Bob and Venessa share $52. if Bob gets three times what Venessa gets, how much does he get?​

Answers


Answer is 39

Venessa- x
Bob- 3x
3x+x=52
4x=52
x=13 (Venessa)
3x=3*13=39 $ (Bob)

help please and explain (no links and random answers for points)

Answers

Answer:

No 2 answer is 6\8 i.e 3\4 for the one eaten and 2\8 i.e 1\4 for the left over

my noluv.joel15 who wanna follow

Answers

I will follow you later

Please help, I’m confused

Answers

Answer:

220/221

Step-by-step explanation:

cos math

Please I need helpppp

Answers

8x + 3y = 45 * -2 Negative
2x + 3y = 27 * 8 Positive

-16x - 6y = 90
16x + 24y = 216

24y is equal to 216
y is equal to 216/or 24
y is equal to 9

Which means:
8 + 3y = 216
y = 216/24
y = 9


8x + 3y = 45
8x + 3 (Which is 9) = 45

So the Answer is:
8x=45 - 27
8x= 18
X=18/8
X= 2.25



Hope this helps you
(Good Luck)

Canine Crunchies Inc. (CCI) sells bags of dog food to warehouse clubs. CCI uses an automatic filling process to fill the bags. Weights of the filled bags are approximately normally distributed with a mean of 45 kilograms and a standard deviation of 1.2 kilograms.

Requried:
a. What is the probability that a filled bag will weigh less than 49.5 kilograms?
b. What is the probability that a randomly sampled filled bag will weight between 48.5 and 51 kilograms?
c. What is the minimum weight a bag of dog food could be and remain in the top 15% of all bags filled?
d. CCI is unable to adjust the mean of the filling process. However, it is able to adjust the standard deviation of the filling process. What would the standard deviation need to be so that no more than 2% of all filled bags weigh more than 52 kilograms?

Answers

Answer:

a) 0.9999 = 99.99% probability that a filled bag will weigh less than 49.5 kilograms

b) 0.0018 = 0.18% probability that a randomly sampled filled bag will weight between 48.5 and 51 kilograms.

c) 46.24 kilograms

d) The standard deviation would have to be of 3.41 kilograms.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Mean of 45 kilograms and a standard deviation of 1.2 kilograms.

This means that [tex]\mu = 45, \sigma = 1.2[/tex]

a. What is the probability that a filled bag will weigh less than 49.5 kilograms?

This is the pvalue of Z when X = 49.5. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{49.5 - 45}{1.2}[/tex]

[tex]Z = 3.75[/tex]

[tex]Z = 3.75[/tex] has a pvalue of 0.9999

0.9999 = 99.99% probability that a filled bag will weigh less than 49.5 kilograms

b. What is the probability that a randomly sampled filled bag will weight between 48.5 and 51 kilograms?

This is the pvalue of Z when X = 51 subtracted by the pvalue of Z when X = 48.5.

X = 51

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{51 - 45}{1.2}[/tex]

[tex]Z = 5[/tex]

[tex]Z = 5[/tex] has a pvalue of 1

X = 48.5

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{48.5 - 45}{1.2}[/tex]

[tex]Z = 2.92[/tex]

[tex]Z = 2.92[/tex] has a pvalue of 0.9982

1 - 0.9982 = 0.0018

0.0018 = 0.18% probability that a randomly sampled filled bag will weight between 48.5 and 51 kilograms.

c. What is the minimum weight a bag of dog food could be and remain in the top 15% of all bags filled?

This is the 100 - 15 = 85th percentile, which is X when Z has a pvalue of 0.85. So X when Z = 1.037

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.037 = \frac{X - 45}{1.2}[/tex]

[tex]X - 45 = 1.037*1.2[/tex]

[tex]X = 46.24[/tex]

46.24 kilograms.

d. CCI is unable to adjust the mean of the filling process. However, it is able to adjust the standard deviation of the filling process. What would the standard deviation need to be so that no more than 2% of all filled bags weigh more than 52 kilograms?

X = 52 would have to be the 100 - 2 = 98th percentile, which is X when Z has a pvalue of 0.98, so X when Z = 2.054. We would need to find the value of [tex]\sigma[/tex] for this.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]2.054 = \frac{52 - 45}{\sigma}[/tex]

[tex]2.054\sigma = 7[/tex]

[tex]\sigma = \frac{7}{2.054}[/tex]

[tex]\sigma = 3.41[/tex]

The standard deviation would have to be of 3.41 kilograms.

What is the factored form of x^3 - x^2 - 30x?

Answers

Answer:

x(x − 6) (x + 5)

Step-by-step explanation:

this is the factored form of x^3 - x^2 - 30x

hope this helps and is right :)

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