According to a Pew Research Center study, in May 2011, 43% of all American adults had a smart phone (one which the user can use to read email and surf the Internet). A communications professor at a university believes this percentage is higher among community college students. She selects 355 community college students at random and finds that 162 of them have a smart phone. Then in testing the hypotheses: H 0 : p = 0.43 versus H a : p > 0.43, what is the test statistic? z = . (Please round your answer to two decimal places.)

Suppose a math teacher takes a sample of 169 students and calculates their mean math test score to be 78. suppose it is known that the test score is distributed normally with standard deviation of 9.

a. Give 90% confidence interval for u, the population mean, for the average math test score.

b. Interpret the interval in part a. in terms of the problem.

c. what is the value of z for a 98% confidence interval?

d.What is the value of z for 96% confidence interval?

e. How many students must be sampled in order to estimate u within +- 0.2 degree with 90% confidence?

The times that college students spend studying per week have a distribution that is skewed to the right with a mean of 7.0 hours and a standard deviation of 2.4 hours. Find the probability that the mean time spent studying per week for a random sample of 45 students would be

a. between 7.4 and 8.2 hours.

b. less than 7.4 hours

. Note 1: Round your z values to 2 decimal places before looking them up in the table or using them in a calculator. Note 2: Keep 4 decimal places in your final answers.

A group of 501 students took the college entrance exam, and had a mean score of
372 and a standard deviation of 27. Suppose a random sample of 81 students is
selected.
A. If the sampled population is not very large, we need to make an adjustment in
the calculation of standard error. Explain why.
B. Under what condition do we need to make an adjustment in the calculation of
standard error? Check if this condition holds.
C. What is the distribution of sample mean after the adjustment?
D. What is the probability that the sample mean score is greater than 365?

While the implementation plan prepares students to apply their research to the problem or issue of prevention of central line associated blood stream infections CLABSI in skilled nursing and rehabilitation centers

A literature review analyzes how current research supports the PICOT, as well as identifies what is known and what is not known in the evidence. Students will use the information from the earlier PICOT Statement Paper and Literature Evaluation Table assignments to develop a 750-1,000 count review that includes the following sections:

problem of prevention of central line associated blood stream infections CLABSI

According to a Pew Research Center study, in May 2011, 39% of all American adults had a smartphone (one which the user can use to read email and surf the Internet). A communications professor at a university believes this percentage is higher among community college students. She selects 342 community college students at random and finds that 139 of them have a smartphone. Then in testing the hypotheses: H0 : p = 0.39 versus Ha : p > 0.39

What is the test statistic?

z =  

(Please round your answer to two decimal places.)

The CHE reported that 60% of those responding to a national survey of college freshmen were attending the college of their first choice. Suppose that 500 students responded to the survey the actual sample size was much larger.

a) Using the sample size of 500, calculate a 98% confidence interval for the proportion of college students who were attending their first choice of college.

b) The actual sample size of survey was much larger than 500. Would a confidence interval based on the actual sample size have been narrower or wider than the one computed in part a?

Online courses: A sample of 266
students who were taking online courses were asked to describe their overall impression of online learning on a scale of 1–7, with 7 representing the most favorable impression. The average score was 5.65 , and the standard deviation was 0.95.

(a) Construct a 99% confidence interval for the mean score.

(b) Assume that the mean score for students taking traditional courses is 5.58 . A college that offers online courses claims that the mean scores for online courses and traditional courses are the same. Does the confidence interval contradict this claim? Explain

A certain test preparation course is designed to help students improve their scores on the GMAT exam. A mock exam is given at the beginning and end of the course to determine the effectiveness of the course. The following measurements are the net change in 4 students' scores on the exam after completing the course: 11,13,9,8 Using these data, construct a 90% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal. Step 3: Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

For a certain year a study reports that the percentage of college students using credit cards was 87%. A college dean of student services claims that this is too high for her university, so she randomly selects 50 students and finds that 40 of them use credit cards. At  = 0.10 is she correct?

State:__________________________________ CV: use table E, F, G, CV=___________________ TV: z, t, or 2  (circle one), TV=________________ Decide:________________________________ Summary: (remember to circle the correct description before completing the statement) There is/is not enough evidence to reject/support the claim that______________________ ________________________________________________________________________ _______________________________________________________________________