Philip and his good buddy Leroy are both mechanics at a shop that does oil changes. They are in a friendly competition to see who can complete the most oil changes in one day. Philip has already finished 3 oil changes today, and can complete more at a rate of 1 oil change per hour. Leroy just came on shift, and can finish 2 oil changes every hour. Sometime during the day, the friends will be tied, with the same number of oil changes completed. How many oil changes will Philip and Leroy each have done? How long will that take?

(20 points) a bank has been receiving complaints from real estate agents that their customers have been waiting too long for mortgage confirmations. the bank prides itself on its mortgage application process and decides to investigate the claims. the bank manager takes a random sample of 20 customers whose mortgage applications have been processed in the last 6 months and finds the following wait times (in days): 5, 7, 22, 4, 12, 9, 9, 14, 3, 6, 5, 15, 10, 17, 12, 10, 9, 4, 10, 13 assume that the random variable x measures the number of days a customer waits for mortgage processing at this bank, and assume that x is normally distributed. 2a. find the sample mean of this data (x ě…). 2b. find the sample variance of x. find the variance of x ě…. for (c), (d), and (e), use the appropriate t-distribution 2c. find the 90% confidence interval for the population mean (îľ). 2d. test the hypothesis that îľ is equal to 7 at the 95% confidence level. (should you do a one-tailed or two-tailed test here? ) 2e. what is the approximate p-value of this hypothesis?

Astudent showed the steps below while solving the inequality |x-4|< 1 by graphing.

Compute the standard deviation of the following set of data to the nearest whole number. 10, 10, 15, 20, 25