A researcher is interested in the decrease in adolescent BMI after a new after school program is implemented to promote exercise in children. Suppose the researcher wants to collect a SRS of children from the program in order to evaluate their loss in BMI. If the population standard 22 deviation is 4.87 kg/m , and the researcher wants to capture the mean BMI within 4 kg/m , how many children should he sample to attain 95% confidence?

A union of restaurant and foodservice workers would like to estimate the mean hourly wage, μ, of foodservice workers in the U.S. this year The mean hourly wage last year was $8.16, and there is good reason to believe that this year's value is different from last year's.The union decides to do a statistical test to see if the value has indeed changed. The union chooses a random sample of this year's wages, computes the mean of the sample to be $8.43, and computes the standard deviation of the sample to be $1.25. Based on this information, complete the parts below. Suppose the true mean hourly wage for foodservice workers in the U.S. this year is $8.16. Fill in the blanks to describe a Type I error. 1. A Type I error would be (rejecting) or (failing to reject) the hypothesis       2. That μ is (less than) (less than or = to) (greater than) (greater than or = to) (not = to) or (= to)       3. The number (1.25), (8.43), or (8.16)   4. When, in fact, μ is (= to 1.25) (= to 8.43) (= to 8.16)…

An article appeared in an Australian newspaper. It described a study of academic performance and attention span and reported that the mean time to distraction for teenage boys working on an independent task was 3 minutes. Although the sample size was not given in the article, suppose that this mean was based on a random sample of 50 teenage Australian boys and that the sample standard deviation was 1.7 minutes. Is there convincing evidence that the average attention span for teenage boys is less than 4 minutes? Test the relevant hypotheses using a = 0.01. (Use a statistical computer package to calculate the P-value. Round your test statistic to two decimal places and your P-value to four decimal places.) t = P-value = State the conclusion in the problem context. Do not reject Ho. We do not have convincing evidence that the mean time to distraction for Australian teenage boys is less than 4 minutes. Reject Ho. We have convincing evidence that the mean time to distraction for Australian…

A researcher was interested in comparing the resting pulse of people who exercise regularly and people wo do not exercise regularly. Independent simple random samples of 16 people ages 30-40 who do no exercise regularly and 12 people ages 30-40 who exercise regularly were selected, and the resting pulse rate of each person was measured. The summary statistics are as follows. Do not exercise  Do exercise X1= 73.9 X2= 69.1 S1= 10.9 S2= 10.9  N1= 16 N2=12 1. Verify the conditions needed to proceed with hypothesis testing or Confidence intervals. 2. At the 5% significance level, do the data provide sufficient evidence to conclude that the mean resting pulse rate of people who do not exercise regularly is greater than the mean resting pulse rate of people who exercise regularly? State your null, alternate hypothesis, calculate the test statistic, determine your decision and interpret your decision. 3. Find the 95% confidence interval around the difference between the sample…

A sample of n = 4 scores has a variance of s2 = 64. What is the estimated standard error for the sample mean? Group of answer choices sM = 1 sM = 2 sM = 4 sM = 16

The amounts of time students study for an exam follows a normal model with a mean of 6 hours and a standard deviation of 1.5 hours. what is the probability a student studies between 3.5 and 5.5 hours?

An independent-measures study produced sample mean of M1 = 20 and M2 = 17.  If both samples have n= 18 scores and Cohen’s d = .50, what is the value for the pooled variance?

A therapist would like to evaluate an intervention for treating depression.  A sample of n = 20 depressed clients is obtained, and each person’s level of depression is measured using a standardized questionnaire before they begin the therapy program.  Two weeks after therapy, each client’s level of depression is measured again.  The average level of depression dropped by 4.0 points following therapy.  The difference scores had a variance of 64.  Identify and Cclculate the appropriate test statistic.Make sure to report the degrees of freedom for the statistical test (if appropriate).  You must show your work to receive full credit. State your conclusions (use a two-tailed test with a = .05 for all tests). Compute an effect size.

If all participants in a repeated measures research study show roughly the same difference between treatments, then the data will produce a statistically significant value for the t statistic. True or false

A sample of seven laptop computers had a variance of 25.88 years when the lifespan of the computer was studied.  Find the 90% confidence interval for the true variance of the lifespan of laptop computers.  Show all work leading up to your answer below