Daily Newspapers A survey was taken of the num- ber of daily newspapers a person reads per day. Find the mean, variance, and standard deviation of the distribution. 0 2 P(X) 0.42 0.35 0.20 0.03

Use the display of data to find the standard deviation. Frequency 12- 10- 8- 6- 4- 2- 0- Score 5 6 7 8 9 10 11 The standard deviation is approximately (Do not round until the final answer. Then round to the nearest hundredth as needed.)

Summary data Fall semester Spring semester 27 72.4 Number of students 26 69.7 11 Mean final exam score Standard deviation final exam 9.1 Score

Age of Senators The average age of senators in the 108th Congress was 57.5 years. If the standard deviation was 14.5 years, find the z-scores corresponding to the oldest and youngest senators of age 85 and 46. Round z scores to two decimal places. The  z -score corresponding to the oldest senator of age  85  is :__________________   .

safety monitors the number of driving on influence arrests and is interested in the distribution of arrests in the month of december over the last 5 years . The data are. 82 71 95 80 97 find the standard deviation

Hospital Emergency Waiting Times The mean of the waiting times in an emergency room is 87 minutes with a standard deviation of 17.3 minutes for people who are admitted for additional treatment. The mean waiting time for 74 minutes with a standard deviation of 9.7 minutes. Which times are more variable? Calculate the coefficient of variation. Round your answers to one decimal place. Additional treatment CVar: ___% Discharged CVar: ___%

Age of Senators The average age of senators in the  108th  Congress was  61  years. If the standard deviation was  12  years, find the  z -scores corresponding to the oldest and youngest senators of age  82  and  43 . Round  z  scores to two decimal places.     Part: 0 / 2 0 of 2 Parts Complete

Salary An employer pays a mean salary for a 5-dayworkweek of $1250 with a standard deviation of $129.On the weekends, his salary expenses have a mean of$450 with a standard deviation of $57. What is the meanand standard deviation of his total weekly salaries?

Ages of Passenger Cars The average age of passenger train cars is 19.4 years. If the distribution of ages is normal and 7% of the cars are older than 21.3 years, find the standard deviation. Round z-value calculations to 2 decimal places and final answer to 2 decimal places. The standard deviation must be years. X Ś

Tossing Coins Find the mean, variance, and standard deviation for the number of heads when 11 coins are tossed. Round your answer to three decimal places.