Assume the distribution of measurements to be approximately normal.

a) Construct a

b) What can we assert with

UkusakazaL
2021-08-04
Answered

A random sample of 100 automobile owners in the state of Virginia shows that an automobile is driven on average 23,500 kilometers per year with a standard deviation of 3900 kilometers.

Assume the distribution of measurements to be approximately normal.

a) Construct a$99\mathrm{\%}$ confidence interval for the average number of kilometers an automobile is driven annually in Virginia.

b) What can we assert with$99\mathrm{\%}$ confidence about the possible size of our error if we estimate the average number of kilometers driven by car owners in Virginia to be 23,500 kilometers per year?

Assume the distribution of measurements to be approximately normal.

a) Construct a

b) What can we assert with

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question2answer

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

a) The

The value of mean is 23,500 kilometres, population standard deviation is 3,900 and sample size

Critical value:

From the standard normal distribution table, for the

The confidence interval formula for the population mean is,

Substitute mean

Thus, the

b) The required formula is obtained below:

Substitute 3,900 for

With

asked 2021-08-09

A clinical trial was conducted to test the effectiveness of a drug for treating insomnia in older subjects. Before treatment, 13 subjects had a mean wake time of 101.0 min. After treatment, the 13 subjects had a mean wake time of 94.6 min and a standard deviation of 24.9 min. Assume that the 13 sample values appear to be from a normally distributed population and construct a

Construct the

What does the result suggest about the mean wake time of 101.0 min before the treatment? Does the drug appear to be effective?

The confidence interval ▼ does not include| includes the mean wake time of 101.0 min before the treatment, so the means before and after the treatment ▼ could be the same |are different. This result suggests that the drug treatment ▼ does not have | has a significant effect.

asked 2021-01-10

The average zinc concentration recovered from a sample of measurements taken in 36 different locations in a river is found to be 2.6 grams per liter. Find the 95% confidence intervals for the mean zinc concentration in the river. Assume that the population standard deviation is 0.3 gram per liter.

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 2021-08-03

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 2021-05-29

People with high blood pressure suffer from hypertension. A study of the lipid profiles of hypertensive patients was carried out and the results published in Biology and Medicine (Vol. 2, 2010). Data on fasting blood sugar (milligrams/deciliter) and magnesium (milligrams/deciliter) in blood specimens collected from 50 patients diagnosed with hypertension were collected. The accompanying MlNlTAB printout gives 90% confidence intervals for the mean fasting blood sugar (FBS) and mean magnesium level (MAG). a. Locate and interpret the 90% confidence interval for mean fasting blood sugar on the printout. b. Locate and interpret the 90% confidence interval for mean magnesium level on the printout. c. If the confidence level is increased to 95%, what will happen to the width of the intervals? d. If the sample of hypertensive patients is increased from 50 to 100, what will likely happen to the width of the intervals?

asked 2020-11-01

Find the critical points of the following functions on the given intervals. Identify the absolute maximum and absolute minimum values (if they exist).
$f\left(x\right)={x}^{3}-6{x}^{2}\text{on}[-1,5]$

asked 2020-11-27

A random sample of 5805 physicians in Colorado showed that 3332 provided at least some charity care (i.e., treated poor people at no cost).

a)

Let p represent the proportion of all Colorado physicians who provide some charity care. Find a point estimate for p. (Round your answer to four decimal places.)

b)

Find a$99\mathrm{\%}$ confidence interval for p. (Round your answer to three decimal places.)

lower limit$=?$

upper limit$=?$

c)

Is the normal approximation to the binomial justified in this problem? Explain

a)

Let p represent the proportion of all Colorado physicians who provide some charity care. Find a point estimate for p. (Round your answer to four decimal places.)

b)

Find a

lower limit

upper limit

c)

Is the normal approximation to the binomial justified in this problem? Explain