finite Math 200 Question Help

7. [-/1 Points] DETAILS TANFIN 12 8.1.022. MY NOTES An examination consisting of ten true-or-false questions was taken by a class of 100 students. The probability distribution of the random variable X, where X denotes the number of questions answered correctly by a randomly chosen student, is represented by the accompanying histogram. The rectangle with base centered on the number 8 is missing. What should be the height of this rectangle? .25 .20 .15 .10 .05 2 9 10 Need Help? Read It 8. [-/9 Points] DETAILS TANFIN 12 8.1.025. MY NOTES PRACTICE ANOTHER The interest rates paid by 30 financial institutions on a certain day for money market deposit accounts are shown in the accompanying table. Rate % 2 2.25 2.55 2.56 2.58 2.60 2.65 2.85 Institutions 1 8 3 7 2 2 Let the random variable X denote the interest rate per year paid by a randomly chosen financial institution on its money market deposit accounts. (a) Find the probability distribution associated with these data. (Round your answers to three decimal places.) Rate % P(X = X) 2 2.25 2.55 2.56 2.58 2.60 2.65 2.85 (b) Find the probability that the interest rate paid by a financial institution chosen at random is less than 2.56% per year. (Round your answer to three decimal places.) Need Help? Read It 9. [-/7 Points] DETAILS TANFIN 12 8.1.034. MY NOTES PRACTICE ANOTHER Suppose the following table gives the age distribution of the U.S. population. Group 5 Age (in years) Under 5 5-19 20-24 25-44 45-64 65 and over Number (in thousands) 21,465 61,776 21,725 81,526 80,438 39,978 Let x denote a random variable that takes on the values 1, 2, 3, 4, 5, and 6 corresponding to the age groups given in the table. (a) Find the probability distribution associated with these data. (Round your answers to three decimal places.) P(X = X) Under 5 5 - 19 3 20-24 25-44 5 45-64 6 65 and over (b) What percentage of the U.S. population is between 5 and 24 years old, inclusive? (Round your answer to three decimal places.)