Can someone explain this to me?

The ratio of men to women working for a company is 4 to 5 . if there are 90 women working for the company, what is the total number of employees?

Use the frequency distribution, which shows the number of american voters (in millions) according to age, to find the probability that a voter chosen at random is in the 18 to 20 years old age range. ages frequency 18 to 20 5.9 21 to 24 7.7 25 to 34 20.4 35 to 44 25.1 45 to 64 54.4 65 and over 27.7 the probability that a voter chosen at random is in the 18 to 20 years old age range is nothing. (round to three decimal places as needed.)

What are the coordinates of the midpoint of ab? ,1/2) /2,-1) ,-3/2) /2,-2)