Find the missing number in each data set, with the mean given.
(Work must be provided for the mean)

Mean = 7.8 | 5, 8, __, 12, 3
Mean = 12 | 9, 12, 15, 21, 4, __
Mean = 74.5% | 91%, 77%, 56%, __, 76%, 61%, 98%, 89%

Astore manager records the total visitors and sales, in dollars, for 10 days. the data is shown in the scatter plot. what conclusion can the store manager draw based on the data? question 3 options: an increase in sales causes a decrease in visitors. an increase in sales is correlated with a decrease in visitors. an increase in visitors is correlated with an increase in sales.

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2