Show working out

5. (Section 2.3) The following frequency distribution provides the number of test scores in each test score range. Find the mean (average) test score. Test scores Frequency 70 - 79 8 80 -89 17 90 - 99 6 6. (Section 2.4) Find the standard deviation of the following data set: 3, 5, 6, 6 7. (Section 2.5) A TV company found that the cost of their products are normally distributed with a mean cost of $800 and a standard deviation of $120. Use this information to answer the questions below. a. 95% of the cost lies between and b. What percentage of the cost lies above $560? 8. (Section 3.1) A box contains 20 pencils. Of those pencils, 4 are blue, 8 are red, and 8 are yellow. If you select a pencil from the box, what is the probability that you will draw a blue or a yellow pencil? 9. (Section 4.3) At 45 years old, John decides to invest in an annuity. The annuity yields a 7% rate, and John plans to contribute monthly for 20 years. How much money must he deposit each month if he wants his account to accumulate to $500,000 after the 20 years