The owner of a local movie theater keeps track of the number of tickets sold in each purchase and makes a probability distribution based on these records. Let X represent the number of tickets bought in one purchase. The distribution for X is given in the table. Number of Tickets 1 2 3 4 5 Probability 0 29 0.44 0.19 0.06 0.02 Which is the correct interpretation of the standard deviation? O The number of tickets purchased typically varies from the expected value by 0.95 tickets. O If many, many purchases are made, the expected number of tickets purchased is 2.1. O The mean number of tickets purchased typically varies from the expected value by 0.95 tickets. O The mean number of tickets purchased typically varies from the expected value by 0.89 tickets.

The random variable X is the crew size of a randomly selected shuttle mission. Its probability distribution is shown below. Complete parts a through c. 2 5 6 7 8 D 4 0.045 0.306 P(X=x) 0.025 0.187 0.431 0.006 ... a. Find and interpret the mean of the random variable. μ= 5.947 (Round to three decimal places as needed.) Interpret the mean. Select the correct choice below and fill in the answer box to complete your choice. (Round to three decimal places as needed.) A. The average number of persons in a shuttle crew is 5.947 person(s). OB. The most common number of persons in a shuttle crew is person(s). b. Obtain the standard deviation of the random variable. O (Round to three decimal places as needed.) Check answer Help me solve this View an example Get more help. 30 20 F10 F4 MacBook Air F6 DII FB Clear all DD F9

Assume that adults have IQ scores that are normally distributed with a mean of μ=105 and a standard deviation σ=15. Find the probability that a randomly selected adult has an IQ between 90 and 120.   Click to view page 1 of the table. LOADING... Click to view page 2 of the table. LOADING...         Question content area bottom Part 1 The probability that a randomly selected adult has an IQ between 90 and 120 is enter your response here. ​(Type an integer or decimal rounded to four decimal places as​ needed.)

Cody took his first physics exam and scored an 80. The population mean for this exam is 70, and the standard deviation is 5. What is the probability of selecting a person with a score greater than Cody’s?

Subpart A,B,C

Historical data show that customers who download music from a popular Web service spend approximately ​$24 per​ month, with a standard deviation of ​$4. Assume the spending follows the normal probability distribution. Find the probability that a customer will spend at least ​$20 per month. How much​ (or more) do the top 7​% of customers​ spend?   What is the probability that a customer will spend at least $20 per​ month?

A stock can earn a return of 10%, 15%, -5%, or 0%, each with a known probability of 25%. What is the standard deviation of this stock's return? Select one: O a. .025 b. .079 c..05 d. .00625 e..0913