approximately 60% of his or her maximum heart rate. For 20-year-olds, this rate is approximately 120 bpm. A simple random sample of thirty 20-year-olds was taken, and the sample mean was found to be 107 bpm, with a standard deviation of 45 bpm. Researchers wonder if this is evidence to conclude that the expected level is actually lower than 120 bpm. Choose the test statistic: MSG O F = MSE -Ho O = (0-E) O x? = E() p-Po O z= Po(1-Po

On the PSAT test taken by about 1.5 million high school juniors each year, the mean score on the reading portion of the test was 46.9, with a standard deviation of 10.9. The scores are normally distributed. If a student needed a score on this portion of the test that put them in the top 5% of scores nationally to qualify for a particular scholarship, what is the minimum score they must achieve?

Almost all medical schools in the United States require students to take the Medical College Admission Test (MCAT). The total scores follow a normal distribution with a mean of ?=25.0and standard deviation of ?=6.4. What is the probability that the population scores are between 18.1 and 30.9?

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?

In the class of 2019, more than 1.6 million students took the SAT. The distribution of scores on the math section (out of 800) is approximately normal with a mean of 528 and standard deviation of 117.  What proportion of students earned scores between 500 and 600 on the SAT math test?

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.

It is believed that nearsightedness affects 14% of children in a certain region. A school district tests the vision of 180 incoming kindergarten children. How many would be expected to be nearsighted? What is the standard deviation for the number of nearsighted children in such a group? You may assume that the children are independent of each other. The mean is? and the standard deviation is?

A bottled water distributor wants to determine whether the mean amount of water contained in​ 1-gallon bottles purchased from a nationally known water bottling company is actually 1 gallon. You know from the water bottling company specifications that the standard deviation of the amount of water is 0.02 gallon. You select a random sample of 50 ​bottles, and the mean amount of water per​ 1-gallon bottle is 0.992 gallon. What is the test​ statistic?

a mathematics assessment test has a mean score of 100 points with a standard deviation of 10 points. what does a person have to be in the top 2.5% of people who have completed the exam? (Assume a normal distribution).

Historically, the mean age of all Memphis residents has been 40 years.  You believe this has changed.  You take a random sample of 130 Memphis residents and find that their mean age is 36 years with a standard deviation of 17 years.  Can you conclude that the mean age of all Memphis residents has changed from 40 years. For the hypothesis testing scenario above, compute the test statistic. For the hypothesis testing scenario above, you conclude that the mean age of all Memphis residents has changed from 40 years at the 0.05 significance level.  Compute the 95% confidence interval to estimate the mean age of all Memphis residents.