the manager went over the sales of mobile phones at the store and found that the mean sale was 45, with a standard deviation of 4. on a particular day, 52 mobile phones were sold.
what is the z-score of the sale of mobile phones on that day?

Aparallelogram has two side lengths of 5 units. three of its sides have equations y = 0, y = 2, y = 2x. find the equation of the fourth side.

What’s the domain of this function? fast

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?