Incidence reflects the likelihood of developing a disease among a group of participants free of the disease who are considered at risk of developing the disease over a specified observation period; prevalence involves estimating the proportion of people who have disease at a point in time.  True  False

In a 2015 study entitled How Undergraduate Students Use Credit Cards, it was reported that undergraduate students have a mean credit card balance higher than $3000. This figure was an all-time high and had increased 42% over the previous five years. Assume that a current study is being conducted to determine if it can be concluded that the mean credit card balance for undergraduate students has continued to increase compared to the report. They want to test to see if the balance for students in 2019 is higher than the balance for students in 2015. See the sample below of undergraduate students in 2015 and different undergraduate students in 2019.    Credit Card Increase Students in 2015 Students in 2019 2500 3300 2200 5450 1500 8000 930 2000 5300 870 1150 250 2700 3000 3300 2200 What can we conclude from this t-test?        a) Reject the null hypotesis OR Fail to reject the null hypotesis? b) We can conclude that the student balance in 2019 are significatly…

Question: A region's department of transportation is deciding whether to increase overnight traffic patrols for a stretch of expressway within the region. The residents who live near the expressway have complained that drivers travel faster at night than during the day. Several years ago, the department tested the claim that the population mean speed of drivers who travel on that stretch of expressway at night is greater than the population mean speed of drivers who travel during the day. Although the results were inconclusive, the department has access to the population standard deviations. The department assumes that the population standard deviation is 4.11 mph for drivers traveling at night and 3.92 mph for drivers traveling during the day. The department decides to conduct the test again by installing an automated speed gun on the stretch of expressway that randomly selects vehicles and records their speed. One sample contains the speed, in miles per hour, of the cars driving…

The Energy Star rating system is an energy efficiency program run by the U.S. Environmental Protection Agency (EPA)Energy Star certified appliances, such as televisions and refrigerators, are rated in regard to their average energy consumption per year. A certain brand of Energy Star certified refrigerator is stated to have a mean yearly electricity cost of $99. A consumer advocacy organization believes that this claim is wrong, that the energy consumption of this particular refrigerator is different than $99 per year. The group collected a random sample of 16 refrigerators of the model in question and had each lab-tested for electricity consumption. The yearly energy consumption of each is given below. 96.7697.898.67 95.52 97.8 95.896.9299.57 97.64 95.46 98.03 96.42 99.32 98.99 95.2197.12 Using alpha = 0.1 , test the hypothesis that the average yearly electricity consumption of the refrigerator in question is different than $99 per year. Assume that the distribution of all electricity…