Hello, anyone know how to do question 20 and 22 (with steps pls) This is due tomorrow

Which of the following is a proper fraction? a. 9⁄8 b. 5⁄6 c. 7⁄3 d. 4⁄2

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%