A. Construct a

B. Construct a

UkusakazaL
2021-08-02
Answered

A simple random sample is drawn from a population that is known to be normally distributed. The sample variance, s2, is determined to be 12.6

A. Construct a$90\mathrm{\%}$ confidence interval for $\sigma$ if the sample size, n, is 20. (Hint: use the result obtained from part (a)) 7.94 (LB) & 23.66 (UB))

B. Construct a$90\mathrm{\%}$ confidence interval for $\sigma$ if the sample size, n, is 30. (Hint: use the result obtained from part (b)) 8.59 (LB) &. 20.63 (UB)

A. Construct a

B. Construct a

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question2answer

Answered 2021-08-17
Author has **155** answers

Step 1

Here

Therefore

Part A

For

So the

So the upper and lower bounds are given by:

Part B

For

So the

So the upper and lower bounds are given by:

asked 2020-12-27

Consider the next 1000 98% Cis for mu that a statistical consultant will obtain for various clients. Suppose the data sets on which the intervals are based are selected independently of one another. How many of these 1000 intervals do you expect to capture the corresponding value of $\mu ?$

What isthe probability that between 970 and 990 of these intervals conta the corresponding value of ? (Hint: Let

Round your answer to four decimal places.)

‘the number among the 1000 intervals that contain What king of random variable s 2) (Use the normal approximation to the binomial distribution

What isthe probability that between 970 and 990 of these intervals conta the corresponding value of ? (Hint: Let

Round your answer to four decimal places.)

‘the number among the 1000 intervals that contain What king of random variable s 2) (Use the normal approximation to the binomial distribution

asked 2021-08-03

A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is $\sigma =15$

a) Compute the$95\mathrm{\%}$ confidence interval for the population mean. Round your answers to one decimal place.

b) Assume that the same sample mean was obtained from a sample of 120 items. Provide a$95\mathrm{\%}$ confidence interval for the population mean. Round your answers to two decimal places.

c) What is the effect of a larger sample size on the interval estimate?

Larger sample provides a-Select your answer-largersmallerItem 5 margin of error.

a) Compute the

b) Assume that the same sample mean was obtained from a sample of 120 items. Provide a

c) What is the effect of a larger sample size on the interval estimate?

Larger sample provides a-Select your answer-largersmallerItem 5 margin of error.

asked 2021-08-12

In a science fair project, Emily conducted an experiment in which she tested professional touch therapists to see if they could sense her energy field. She flipped a coin to select either her right hand or her left hand, and then she asked the therapists to identify the selected hand by placing their hand just under Emily's hand without seeing it and without touching it. Among 358 trials, the touch therapists were correct 172 times. Complete parts (a) through (d).

a) Given that Emily used a coin toss to select either her right hand or her left hand, what proportion of correct responses would be expected if the touch therapists made random guesses? (Type an integer or a decimal. Do not round.)

b) Using Emily's sample results, what is the best point estimate of the therapists' success rate? (Round to three decimal places as needed.)

c) Using Emily's sample results, construct a

Round to three decimal places as needed - ?

asked 2021-03-09

In a study of the accuracy of fast food drive-through orders, Restaurant A had 298 accurate orders and 51 that were not accurate. a. Construct a 90% confidence interval estimate of the percentage of orders that are not accurate. b. Compare the results from part (a) to this 90% confidence interval for the percentage of orders that are not accurate at Restaurant B:

asked 2020-10-18

Consider the following function.
$f\left(x\right)=\frac{{x}^{2}}{{x}^{2}-81}$
a) To find the critucal numbers of f.
b) To find the open interval on which function is increasing or decreasing.
c) To identify the relative extremum.

asked 2022-04-14

Find CI for mean of linear regression with variance unknown

For the simple linear regression model:

$Y}_{i}=\beta \cdot {X}_{i}+{\u03f5}_{i$

I want to find CI for$\beta x$ which is $E\left({Y}_{i}\right)$ when ${x}_{i}=x$ .

I find that$\hat{\beta}\sim N(\beta ,\frac{{\sigma}^{2}}{\sum \left({X}_{i}^{2}\right)})$ , so the distribution of $\beta$ x is N($\beta x,\frac{{X}^{2}{\sigma}^{2}}{\sum \left({X}_{i}^{2}\right)})$ . If the variance is known I can use $P(-{z}_{\frac{\alpha}{2}}\le \frac{\hat{\beta}x-\beta x}{x\frac{\sigma}{\sum}\left({x}_{i}^{2}\right)}\le {z}_{\frac{\alpha}{2}})$ .

If the variance is unknown, what unbiased estimator should I use for$\sigma}^{2$ ? Is it the sample variance? What is it in this case?

For the simple linear regression model:

I want to find CI for

I find that

If the variance is unknown, what unbiased estimator should I use for

asked 2022-03-25

Confidence Intervals, Proportion Estimations

In a study of perception, 107 men are tested and 24 are found to have red/green color blindness.

(a) Find a 92% confidence interval for the true proportion of men from the sampled population that have this type of color blindness.

(b) Using the results from the above mentioned survey, how many men should be sampled to estimate the true proportion of men with this type of color blindness to within 2% with 98% confidence?

(c) If no previous estimate of the sample proportion is available, how large of a sample should be used in (b)?

I have already answered (a). However, I am at a complete loss as to how to answer (b) or (c). For one thing, I am not quite sure what (b) is even asking. Advice on this question would be greatly appreciated.

In a study of perception, 107 men are tested and 24 are found to have red/green color blindness.

(a) Find a 92% confidence interval for the true proportion of men from the sampled population that have this type of color blindness.

(b) Using the results from the above mentioned survey, how many men should be sampled to estimate the true proportion of men with this type of color blindness to within 2% with 98% confidence?

(c) If no previous estimate of the sample proportion is available, how large of a sample should be used in (b)?

I have already answered (a). However, I am at a complete loss as to how to answer (b) or (c). For one thing, I am not quite sure what (b) is even asking. Advice on this question would be greatly appreciated.