9.DNP student David works at CANCARE, a cancer fund-raising organization. The organization has been experimenting with being open from extended hours on weekends (Friday through Sunday). They collected data from 10 weekends at 6 sites, varying the number of hours each weekend. The staff knows that if they are open longer, there is more opportunity for people to visit and to donate, but it also costs a lot more to get people to work nights and on Sundays. Members of the board wanted to find the optimal number of hours given the cost of being open (utilities, salaries, overtime, etc.).

David ran a regression analysis in SPSS to assess the relationship between hours (X) and amount of money (Y) delivered to cancer fund (after paying for utilities, salaries, overtime, etc.). The SPSS results table says: R = .947, R square = .896, Std Error of the Estimate = $5945.45, B for constant = -4188.31, B for hours = 957.02, t for hours = 28.20, p < .001, 95% CI[889.61,1024.43].

Use the regression formula Y' = a + b(X) to estimate the amount of money delivered if the organization is open 36 hours on weekends.

$30,264

$38,640

$41,748

$53,232

$61,608

10-DNP student Jin has collected data in his practice on how long an artificial knee lasts and how much weight patients lose after surgery (because they are more mobile with the new knee). Which of the following facts about his data is a violation of the assumptions of regression analysis (making it difficult to analyze the relationship between weight loss and life of the artificial knee)?

The data on the life of the artificial knee were normally distributed.

The data were randomly sampled from all patients who had knee replacements.

The plot of weight loss and life of the artificial knee showed heteroscedasticity.

The data consisted of paired samples of data from each patient.

None of the above is a violation