1.131 Find more values of z. The variable Z has a stan- dard Normal distribution. (a) Find the number z that has cumulative proportion 0.78. (b) Find the number z such that the event Z > z has proportion 0.22.

A college alumni Organization sent a survey to all recent graduates to ask their annual income. 20% of the alumni responded, and their mean annual income was $40,000  with a standard deviation of $10,000. Explain why these data should not be used to construct a confidence interval for the mean annual income of all recent graduates.

You take a simple random sample of size 25 from a very large population in which the true proportioni p=0.1. Which statement below best describes what you know about the sampling distribution of p? (0.1)(0.9) (a) H,-0.1; o,- the distribution is skewed right. 25 (0.1)(0.9). 25 (b) H,=0.1; o,=. ; the distribution is skewed left. (0.1)(0.9). (c) ,=0.1; o,= the distribution is approximately Normal. %3D 25 (0.1)(0.9) (d) , the distribution is not approximately Normal. 25 =0.1; we cannot use the formula o, (0.1)(0.9) ; the distribution is approximately Normal. 25 (e) =0.1; we cannot use the formula o,

A researcher wanted to determine whether certain accidents were uniformly distributed over the days of the week. The data show the day of the week for n = 296 randomly selected accidents. Is there reason to believe that the accident occu with equal frequency with respect to the day of the week at the a = 0.05 level of significance? E Click the icon to view the table. Distribution of accidents Day of the Week Frequency Sunday Monday Tuesday Wednesday Thursday Friday Saturday o 39 37 31 40 39 51 59 Print Done Compute the expected counts for day of the week Day of the Week Observed Count Sunday Expected Count 39 Monday 37 Tuesday 31 Wednesday 40 Thursday 39 Friday 51 Saturday 59 (Round to two decimal places as needed.) ?) Question Viewer Enter your answer in the edit fields and then click Check Answer. Check Answer Clear All parts 3 remaining MacBook Air DD 12 80 888 F9 10 F7 FS F4 esc F2 F3 F1 & 2$ % de %3D @ # 7 8 1 3 4 Y Q W E R tab J K S D ns lock く .. .- つ エ