Part A According to this two-way frequency table, how many 9th graders like rock?

Rock Rap Totals
Grade 9 ? 6 10
Grade 10 30 10 40
Totals 34 16 50

number of 9th graders who like rock =

Part B
What percent of the students in Part A are 10th graders?
A. 90%
B. 80%
C. 20%
D. 10%
Part C
Complete the table for the conditional relative frequencies.

Rock Rap Totals
Grade 9 40% 60% 100%
Grade 10 ? ? 100%
Totals 68% 32% 100%

(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?