Logan is doing a project for his local city planning department in which he tests ...

Q2-The results of a test are normally distributed. If a score of 624 corresponds to the 80th percentile, and a score of 710 corresponds to the 90th percentile, what are the mean and standard deviation of the distribution?

Q6-Logan is doing a project for his local city planning department in which he tests the claim that the city’s housing project contains family units of average size. A random sample of 80 homes in the project shows a sample mean of 3.4 people per family unit with a sample standard deviation of 1.4 people. Construct a hypothesis test to determine whether the average size if family units in the housing project is different from the national average of 3.8. use a=0.01

Q7-After evaluating several dozen randomly chosen light bulbs of the same type from different manufacturers, a statistician determined that here was a linear correlation coefficient of 0.80 when plotting cost (in dollars) versus bulb life (in hours). The least-squares regression line had a slope of 1084 and a y-intercept of -35.4  Question What would be the appropriate life expectancy of a bulb that costs $ 0.95?