When engaging in weight-control (fitness/fat burning) types of exercise, a person is expected to attainapproximately 60% of his or her maximum heart rate. For 20-year-olds, this rate is approximately 120bpm. A simple random sample of thirty 20-year-olds was taken, and the sample mean was found to be107 bpm, with a standard deviation of 45 bpm. Researchers wonder if this is evidence to concludethat the expected level is actually lower than 120 bpm.Find the sample size that will guarantee 80% power if we want to detect a difference between107 bpm and 120 bpm.5596109O 76

Answered: approximately 60% of his or her maximum…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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You may need to use the appropriate appendix table or technology to answer this question. Money reports that the average annual cost of the first year of owning and caring for a large dog in 2017 is $1,448. The Irish Red and White Setter Association of America has requested a study to estimate the annual first-year cost for owners of this breed. A sample of 50 will be used. Based on past studies, the population standard deviation is assumed known with o = $245. 1,902 2,042 1,936 1,817 1,504 1,572 1,532 1,907 1,882 2,153 1,945 1,335 2,006 1,516 1,839 1,739 1,456 1,958 1,934 2,094 1,739 1,434 1,667 1,679 1,736 1,670 1,770 2,052 1,379 1,939 1,854 1,913 2,163 1,737 1,888 1,737 2,230 2,131 1,813 2,118 1,978 2,166 1,482 1,700 1,679 2,060 1,683 1,850 2,232 2,294 (a) What is the margin of error for a 95% confidence interval of the mean cost in dollars of the first year of owning and caring for this breed? (Round your answer to nearest cent.) (b) The DATAfile Setters contains data collected…
We are planning on performing a study to determine the average age of online students at NCC. We would like to be 99% confident in our answer and we would like to be within 2 years of the actual age. A previous study determined that the standard deviation was approximately 7.5 years. How many students must we sample?
in a test of a lifelong brand of tires , a survey revealed that the mean life was 35,000 mikes and the standard deviation was 7083 mikes. if the shape of the population distribution is known to be normal, approximately what percentage of the tires lasts less than 20834 miles ?
A particular fruit's weights are normally distributed, with a mean of 696 grams and a standard deviation of 25 grams. If you pick 26 fruits at random, then 4% of the time, their mean weight will be greater than how many grams? Give your answer to the nearest gram.
A health care professional wishes to estimate the birth weights of infants. How large a sample must be selected if she desires to be 95% confident that the true mean is within 10 ounces of the sample mean? The standard deviation of the birth weights is known to be 4 ounces.
A scientist has read that the mean birth weight of babies born at full term is 7.4 pounds. The scentist has good reason to believe that the mean birth weight of babies born at full term, µ, is greater than this value and plans to perform a statistical test. She selects a random sample of birth weights of babies born at full term and finds the mean of the sample to be 7.8 pounds and the standard deviation to be 1.6 pounds. Based on this information, complete the parts below. (a) what are the null hypothesis H, and the alternative hypothesis H, that should be used for the test? Ho :0 O
Loretta, who turns 91 this year, has heard that the mean systolic blood pressure among the elderly is 120 millimeters of mercury (mm Hg), but she believes that the actual value is higher. She bases her belief on a recently reported study of 19 randomly selected, elderly adults. The sample mean systolic blood pressure of the adults in the study was 121 mm Hg , and the sample standard deviation was 20 mm Hg. Assume that the population of systolic blood pressures of elderly adults is normally distributed. Based on the study, at the 0.1 level of significance, can it be concluded that μ , the mean systolic blood pressure among elderly adults, is greater than 120 mm Hg? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (a) State the null hypothesis H0? and the alternative hypothesis H1? . H0:? H1:? (b) Determine the type of test statistic to…
It takes an average of 14.5 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will increase if the patient is immediately told the truth about the injury. The EMT randomly selected 70 injured patients to immediately tell the truth about the injury and noticed that they averaged 16.3 minutes for their blood to begin clotting after their injury. Their standard deviation was 4.75 minutes. What can be concluded at the the α = 0.10 level of significance? a. For this study, we should use [Select an answer b. The null and alternative hypotheses would be: Ho: ? Select an answer H₁: ? Select an answer ✓ c. The test statistic ? = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ? ✓ a f. Based on this, we should [Select an answer the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest the populaton mean is significantly greater than 14.5 at a = 0.10, so…
The president of a college wants to determine the mean number of units that college students take per semester. How large of a sample is required in order to be 99% sure that a sample mean will be off by no more than 1.25 units? An initial study suggested that the standard deviation is approximately 2.1 units.
A manufacturer of car batteries claims that the life of his batteries have a standard deviation equal to 0.9 years if a random sample of 10 of these batteries have a standard deviation of 14.4 months do you think that population standard deviation exceeds 0.81 years. Explain your results.
Executives at a car dealership want to estimate the average age of their customers before making a television commercial. They want to be 90% confident that the mean age is ±2 years of the sample mean. If the standard deviation from a previous study is 12 years, how large should the sample be? 98 ODD 239 4 139

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