Posted: January 24th, 2017

What is the z-value for a random sample of 25 vegans who live to an average age of 73? Does this alter life expectancy at a .05 level of significance?

Given a sample with 5 scores: 4, 6, 8, 10, and y, and the mean of this sample is 6, what is the variance of the sample? (Hint: first find y). Answer 1 points (Extra Credit) Question 2 Given a population mean weight of 150 pounds and a population standard deviation 40 pounds, express an individual weight of 200 pounds as a z-score. (to two decimal places, e.g.: 3.21 or 6.00) Answer 1 points (Extra Credit) Question 3 Find the correlation coefficient for these scores (they are given in the form (x1,y1), (x2,y2) etc): (0,1), (10,3), (4,1), (8,2), (8,3) (express this to 3 decimal places, e.g.: .123 or -.456) Answer 1 points (Extra Credit) Question 4 Use the least squares regression equation to find the predicted Y value for an X value of 5, given: r = .3, SSy=64 , SSx=4 , mean of y= 30, mean of x= 10 Answer 1 points (Extra Credit) Question 5 You’re going skydiving, because you’re awesome. The main parachute has to do two things to keep you alive: release when you pull the cord, (probability of releasing = .9) AND unfold properly (probability of unfolding = .8). Unfolding is independent of releasing. OR, if anything goes wrong, your backup parachute will save you (probability of backup working = .7). The backup parachute only comes into play if the first parachute fails. What is the probability that you survive, i.e. that either your primary OR secondary parachute will work? (Hint: this combines both independent and mutually exclusive events, and the answer will be greater than .9). Give the answer to three decimal places, e.g.: .999 Answer 1 points (Extra Credit) Question 6 Does eating vegetables instead of delicious foods affect how long you live? Given a population life expectancy of 75 years with population standard deviation 5 years, What is the z-value for a random sample of 25 vegans who live to an average age of 73? Does this alter life expectancy at a .05 level of significance? Type the z-value in box 1 to two decimal places (e.g. 3.45), and in box 2 type either yes or no (yes if this is statistically significant and you reject the null, no if it is not significant and you fail to reject the null). Answer 1 points (Extra Credit) Question 7 A similar follow-up study is done on a sample of 25 meat-lovers who never eat vegetables, again randomly selected from the same general population (population mean life expectancy = 75, population standard deviation = 5).