Answer: 44
Step-by-step explanation:53-9
Answer:
31
Step-by-step explanation:
Jiri's age = J
J + (J-9) = 53
2J - 9 = 53
2J = 62
J = 31
Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 148 millimeters, and a standard deviation of 7 millimeters. If a random sample of 31 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by more than 2.2 millimeters? Round your answer to four decimal places.
Answer:
0.0802 = 8.02% probability that the sample mean would differ from the population mean by more than 2.2 millimeters
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
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.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Their current steel bolts have a mean diameter of 148 millimeters, and a standard deviation of 7 millimeters.
This means that [tex]\mu = 148, \sigma = 7[/tex]
Sample of 31:
This means that [tex]n = 31, s = \frac{7}{\sqrt{31}}[/tex]
What is the probability that the sample mean would differ from the population mean by more than 2.2 millimeters?
Less than 148 - 2.2 = 145.8 or more than 148+2.2 = 150.2. Due to the simmetry of the normal distribution, these probabilities are the same, which means that we find one and multiply by 2.
Probability of being less than 145.8:
The pvalue of Z when X = 145.8. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{145.8 - 148}{\frac{7}{\sqrt{31}}}[/tex]
[tex]Z = -1.75[/tex]
[tex]Z = -1.75[/tex] has a pvalue of 0.0401
2*0.0401 = 0.0802
0.0802 = 8.02% probability that the sample mean would differ from the population mean by more than 2.2 millimeters
Which value of c completes the square in the expression x2 + 14x + c?
A.-49
B.-7
C.7
D.49
Find -3(6m-8)+(-4+2m).
Answer: − 16 m + 20
Step-by-step explanation:
Answer:
m = 5/4
Step-by-step explanation:
A geologist examines 18 water samples for iron concentration. The mean iron concentration for the sample data is 0.272 cc/cubic meter with a standard deviation of 0.0851. Determine the 99% confidence interval for the population mean iron concentration. Assume the population is approximately normal. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Answer:
The critical value that should be used in constructing the confidence interval is T = 2.898.
The 99% confidence interval for the population mean iron concentration is between 0.214 cc/cubic meter and 0.33 cc/cubic meter.
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 = 18 - 1 = 17
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.99}{2} = 0.995[/tex]. So we have T = 2.898.
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.898\frac{0.0851}{\sqrt{18}} = 0.058[/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 0.272 - 0.058 = 0.214 cc/cubic meter.
The upper end of the interval is the sample mean added to M. So it is 0.272 + 0.058 = 0.33 cc/cubic meter.
The 99% confidence interval for the population mean iron concentration is between 0.214 cc/cubic meter and 0.33 cc/cubic meter.
can someone help please
Can someone please help thx:)
Answer:
x = 35
Step-by-step explanation:
Angles sum of a triangle = 180
That being said we want to create an equation to solve for x
180 = 2x - 8 + x - 7 + 90 ( there is a right angle indicated by the little square; a right angle has a measure of 90 degrees, so just in case you were wondering that's where the 90 came from )
now we solve for x
step 1 combine like terms
2x + x = 3x
90 - 7 - 8 = 75
now we have 180 = 75 + 3x
step 2 subtract 75 from each side
180 - 75 = 105
75 - 75 cancels out
Now we have 105 = 3x
step 3 divide each side by 3
105 / 3 = 35
3x/3=x
we're left with x = 35
In semiconductor manufacturing, wet chemical etching is often used to remove silicon from the backs of wafers prior to metalization. The etch rate is an important characteristic in this process and known to follow a normal distribution. Two different etching solutions have been compared, using two random samples of 10 wafers for each solution. Assume the variances are equal. The etch rates are as follows (in mils per minute):
Solution 1 Solution 2
9.9 10.6 10.5 10.2
9.4 10.3 10.6 10.2
9.3 10.0 10.7 10.7
9.6 10.3 10.4 10.4
10.2 10.1 10.5 10.3
Required:
a. Construct normal probability plots for the two samples. Do these plots provide support for the assumptions of normality and equal variances? Write a practical interpretation for these plots.
b. Do the data support the claim that the mean etch rate is the same for both solutions? In reaching your conclusions, use α = 0.05 and assume that both population variances are equal. Calculate a P-value.
c. Find a 95% confidence interval on the difference in mean etch rates
im really smart (no im not thats why im here)
A company manufacturing computer chips finds that 8% of all chips manufactured are defective. In an effort to decrease the percentage of defective chips, management decides to provide additional training to those employees hired within the last year. After training was implemented, a sample of 450 chips revealed only 27 defects. A hypothesis test is performed to determine if the additional training was effective in lowering the defect rate. The correct value of the Z-statistic is
Answer:
The correct value of the Z-statistic is z = -1.56
Step-by-step explanation:
A company manufacturing computer chips finds that 8% of all chips manufactured are defective.
This means that the null hypothesis is:
[tex]H_{0}: p = 0.08[/tex]
A hypothesis test is performed to determine if the additional training was effective in lowering the defect rate.
This means that the alternate hypothesis is:
[tex]H_{a}: p < 0.08[/tex]
z-statistic:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
0.08 is tested at the null hypothesis:
This means that [tex]\mu = 0.08, \sigma = \sqrt{0.08*0.92}[/tex]
After training was implemented, a sample of 450 chips revealed only 27 defects.
This means that [tex]n = 450, X = \frac{27}{450} = 0.06[/tex]
The correct value of the Z-statistic is
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{0.06 - 0.08}{\frac{\sqrt{0.08*0.92}}{\sqrt{450}}}[/tex]
[tex]z = -1.56[/tex]
Given that (-3,-1) is on the graph of f(x), find
the corresponding point for the function
f(x-3).
Enter the correct answer.
OOOO
DONE
Clear all
00
G2
Car A is traveling east at a steady speed of 40 miles per hour. After 2 hours, it is 95 miles easy of Jhonstown. Car B is traveling east on the same road. its distance of Jhonstown is represented by the graph.
Answer:
B
Step-by-step explanation:
hope i helped
Hi! I was wondering if someone could explain how to find a percent of a large number. I think you're supposed to multiply a number by a decimal, but I don't remember. Please give an example and no links. Thanks so much!
Answer:
Yes, you're correct.
An example would be, say, 345. You want to find 60%. So you multiply 345 by 0.60.
Answer:
Give other answer brainliest!!!!
Step-by-step explanation:
Good work
It’s the end of the year I’m really not trying so anybody just help really
Answer: its D
Step-by-step explanation: because a - x - is a positive so you add them
Which expression is equivalent to:
−6x+10−16
2(3x+10−8)
−2(3x−5+8)
−2x(3−5+8)
2x(−3−10−8)
Answer:
from the given equation
Step-by-step explanation:
eqn 1 = eqn 3= eqn 4
these all are equivalent
i need help with this
9514 1404 393
Answer:
26
Step-by-step explanation:
The question is asking the fraction equivalent of 0.26 (twenty-six hundredths).
That fraction is 26/100 (twenty-six hundredths). The missing number is 26.
Order these numbers from least to greatest:
|-17|
|-18|
-18
|19|
20
Answer: -18, l-17l, l-18l, l19l, 20
Step-by-step explanation: You can just think of the ones in absolute value brackets as positive.
What do you get when you round 2932.62 to the nearest hundredth please provide step by step explanation too.
Answer:
you get 2932.6
Step-by-step explanation:
you basically just round it down because it isn't 5 or above.
please mark brainliest
Dad spends $227.06 at the grocery store,$95.55 at the shoe store,and $35.16 at the dry cleaners how much did dad spend in all?
Answer:
$357.77
Step-by-step explanation:
Add all of the figures together to find the answer
227.06 + 95.55 + 35.16 = 357.77
Please hurry and solve for 40 points
Answer:
x=3 y=-2
Step-by-step explanation:
Elimination would bring the equation to
3x=18
18/6 is 3
6-3y=12
-3y=6
y=-2
2. How many radians are in a full circle? ?
ON
ㅇ
0 27
ㅇ
Answer:
1 radius in a full circle
Answer: 6.28 radians
Step-by-step explanation: I think pls BRAINLIEST
The logistics/operations manager of a mail order house purchases two products for resale: king beds (K) and queen beds (Q). Each king bed costs $500 and requires 100 cubic feet of storage space, and each queen bed costs $300 and requires 90 cubic feet of storage space. The manager has $75,000 to invest in beds this week, and her warehouse has 18,000 cubic feet available for storage. Profit for each king bed is $300 and for each queen bed is $150. Which of the following is not a feasible purchase combination?
a. 100K - 90Q <= 18,000
b. 90K + 100Q <= 18,000
c. 300K + 90Q <= 18,000
s. 500K + 100Q <= 18,000
e. 100K + 90Q <= 18,000
Answer:
500K + 100Q <= 18,000 ( D )
Step-by-step explanation:
king bed ( K ) requires = 100 cubic feet
Queen bed ( Q ) requires = 90 cubic feet
Total available space = 18,000 cubic feet
Revenue of king size bed = $300
Revenue of queen size bed = $150
Hence the NOT feasible purchase combination
= 500K + 100Q <= 18,000
because 500 of king size bed + 1000 of queen size is > 18,000
Please help
I don't know how to salve it
Answer:
20
Step-by-step explanation:
trust me
Answer:
51.2
Step-by-step explanation:
Since it's a percentage all you have to do is multiply 32 by 1.6 because a 100 percent is equivalent to 1 so 160 percent is equivalent to 1.6.
A vehicle purchased for $29,800 depreciates at a constant rate of 4%. Determine the approximate value of
the vehicle 10 years after purchase. Round to the nearest whole dollar.
Answer:
$44104
Step-by-step explanation:
Given data
Cost = $29800
Rate= 4%
Time= 10years
Applying the formula below, we can find the cost after 10 years as
A=P(1+r)^t
A= 29800(1+0.04)^10
A=29800(1.04)^10
A=29800*1.480
A=$44104
Hence the new cost is $44104
Find arc DC please help me
Answer:
arc ABC = 196°
arc DC = 360 - 196 - 70 = 94° (which looks out of proportion, but so does angle D)
Step-by-step explanation:
arc ABC = 2(∠D) = 2(98°) = 196°
simplify 14x(7xy^14)(-9x^-7 y^-3)
Answer:
-882y^11/x^5
Step-by-step explanation:
What is the answer please help if you put a link I will report
Answer:
true.
Step-by-step explanation:
13 points pls help me quick
Answer:
Right Angles: C, F
Obtuse Angles: E, B
Acute Angles: A, D
Step-by-step explanation:
Right Angles are angles that are exactly 90 degrees.
Obtuse Angles are angles that are bigger than 90 degrees.
Acute Angles are angles that are smaller than 90 degrees.
Answer:
a . C and F .
b. B and E .
c. A and D .
Step-by-step explanation:
Hope this helps .
A simple random sample of 150 people who completed the ESPN 2019 Tournament Bracket was selected, and 81 out of the 150 people who completed the ESPN 2019 Tournament Bracket had their choice to become the national champion make the Final Four. If appropriate, use this information to calculate and interpret a 90% confidence interval for the proportion of all people who completed the ESPN 2019 Tournament Bracket whose choice to become the national champion made the Final Four.
Answer:
The answer is "0.54 and (0.4733, 0.6067)".
Step-by-step explanation:
Please find the complete question in the attachment file.
In question 1:
[tex]\to x=81\\\\ \to n=150\\\\ \to \hat{p}=\frac{x}{n}=\frac{81}{150}=0.54\\\\[/tex]
Hence the choice A is correct.
In point b:
Calculating Critical Value:
[tex]\to (Z_{\alpha/2})=1.64 \ \ \ \ \ \ \ \ \ \ (use \ \ z\ \ table)\\\\[/tex]
Calculating the Confidence intervals:
[tex]=\hat{p} \pm Z_{\alpha/2}\times \sqrt{\frac{\hat{p} \times (1-\hat{p}))}{n}}\\\\ =0.54 \pm 1.64\times \sqrt{\frac{0.0.54 \times (1-0.54)}{150}}\\\\ =0.54 \pm 0.0667\\\\ =(0.4733, 0.6067)\\\\[/tex]
Hence the choice a is correct.
The correct confidence interval is (0.4733, 0.6067).
What is the z critical value?The z critical test is conducted when the population standard deviation on a normal distribution is known and the sample size is greater than or equal to 30.
x = 81
n = 150
p = x/n =81/ 150
p = 0.54
So, the correct choice is A.
In point b
Critical Value:
[tex]Z_{\alpha /2} = 1.64[/tex]
the Confidence intervals:
= p±[tex]Z_{\alpha /2} \times \sqrt{\frac{p \times (1-p)}{n} }[/tex]
= 0.54 ± [tex]\\1.64 \times \sqrt{\frac{0.54 \times (1-0.54)}{150} }[/tex]
= 0.54 ± 0.0667
= (0.4733, 0.6067)
Hence, the choice A is correct.
Therefore, the correct confidence interval is (0.4733, 0.6067).
Learn more about critical value:
https://brainly.com/question/5425085
PLEASE HELP I HAVE NO IDEA HOW TO DO SLOPES
Step-by-step explanation:
(0, 4) (4, 0)
(0-4)/(4-0) = -4/4= -1 is the slope
plese help me
21,382.62 ÷ 10,000
Answer:
2.138262
Please mark my answer as the brainliest for further answers :)
Answer:
2.138262
Step-by-step explanation:
21,382.62 ÷ 10,000
HELP PLEASE IT'S VERY IMPORTANT
Determine the area of the composite figure.
Determine the perimeter of the composite figure.
Answer:
If I did this right the perimeter is 83.7 and the area is 257.1
Explanation:
the perimeter is all sides added so 15+8+8+6.7+20+26 = 83.7
To make adding the area easier, we would separate it into different shapes.
Area of a Triangle: (b x h)/2
(15x9)/2 = 45 since it's a triangle
8x9 = 72
20x6 = 120
(6x6.7)/2 = 20.1 since it's also a triangle
45 + 72 + 120 + 20.1 = 257.1