How do you add on 10% of £1,200how do you add on 10% of £1,200

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%

A50-foot ladder is leaning against a vertical wall. if the base of the ladder is 45 feet from the base of the wall, find the angle the bottling of the ladder makes with the ground.

Write the factored form of this trinomial 9x^2+18x-7