700 doctors went through extra training compared to 1200 doctors who did not. Of the doctors who went through extra training, 125 of them majored in psychology. Of the 1200 doctors who did not do extra training, 174 of them majored in psychology.  Perform a hypothesis test to see if there is a statistically significant evidence that the proportion of doctors who went through extra training is significantly greater than the proportion of doctors who did not.  Perform the test at the alpha = .5 level. What is the p value and conclusion of this test?

A new screening test for Lyme disease is developed for use in the general population. The sensitivity and specificity of the new test are 60% and 70%, respectively. Five hundred people are screened at a clinic during the first year the new test is implemented. Assume the true prevalence of Lyme disease among clinic attendees is 10%. Calculate the predictive value of a positive test.

A newly installed automatic gate system was being tested to see if the number of failures in 1,000 entry attempts was the same as the number of failures in 1,000 exit attempts. A random sample of eight delivery trucks was selected for data collection. Do these sample results show that there is a significant difference between entry and exit gate failures? Use α = 0.05.    Truck 1 Truck 2 Truck 3 Truck 4 Truck 5 Truck 6 Truck 7 Truck 8 Entry failures 40 42 53 55 62 54 50 42 Exit failures 47 52 56 56 60 46 52 45   (b) Find the test statistic tcalc. (Round your answer to 3 decimal places. A negative value should be indicated by a minus sign.) tcalc           (c) Find the critical value tcrit for α = 0.05. (Round your answer to 3 decimal places. A negative value should be indicated by a minus sign.) tcrit          (d) Find the p-value. (Round your answer to 4 decimal places.) p-value

A local coach wants to see if training in light rooms or dark rooms impacts athlete performance. With the single team, the coach tries training in different conditions and takes measurements. She ran her analysis in Microsoft Excel and received the following output table. If the P value is less than 0.05, the null hypothesis may be rejected. Based on the data table, what decision should the coach make about the hypothesis?                  Coach should reject the null hypothesis.   Coach should fail to reject the null hypothesis.     Coach should accept the null hypothesis.    Coach does not have enough information to decide.

An article indicated that the biggest issue facing e-retailers is the ability to turn browsers into buyers. The article stated that less than 10% of browsers buy something from a particular website.   A SRS of 2000 browsers was taken of which 180 made a purchase.  Let alpha =  .10.

Data from the Department of Motor Vehicles indicate that 80% of all licensed drivers are older than age 25. In a sample of n = 50 people who recently received speeding tickets, 33 were older than age 25 and the other 17 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use alpha = .05.   In a sample of n = 50 people who recently received parking tickets, 36 were older than age 25 and the other 14 were age 25 or younger. Is the age distribution for this sample significantly different from the distribution for the population of licensed drivers? Use alpha = .05.

Prior to an intensive TV advertising campaign, the producers of Nike athletic shoes find that 29 of a random sample of 200 upper-income adults are aware of their new leisure shoe line.  A second random sample of 300 such adults is taken after the campaign.  Now 96 of the persons sampled can identify the new line.  Is the increase in the proportion of upper income adults showing brand awareness significant?  Test the claim using alpha = .05.

Foreign freshmen are required to take an English placement exam. Over the past several years, 20% of the new students have failed the test and have been placed in remedial classes. In a sample of n = 100 students from this year’s class, only 12 failed the test.

A team of epidemiologists at the Mayo Clinic wanted to find whether there is an association between obesity and cardiovascular disease (CVD). They conducted a prospective cohort study following obese and non-obese individuals who were free of CVD at the beginning of study for five years. The investigators were also interested in assessing age as a potential confounder, effect modifier, or both. Use the data below to answer the accompanying questions.     CVD No CVD Total Obese 10 90 100 Not Obese 35 465 500 Total 45 555 600       CVD No CVD Total Obese 36 164 200 Not Obese 25 175 200 Total 61 339 400   1. Compute the appropriate measure of association for those who were less than age 50.  2. Compute the appropriate measure of association for those who were older or equal to age 50.  3. Compute the crude measure of association?  4. List three attributes that age must satisfy before it could…