Age (years) Population Under 15 138 15 - 64 6978 Over 64 324 Calculate the old age dependency ratio from the chart above. Round to 4 decimals places.

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

Choose the more precise measurement. 26.4 cm or 8.39 cm

When you flip a biased coin the probability of getting a tail is 0.6. how many times would you expect to get tails if you flip the coin 320 times?