Please help me with this will give you brainliest

What is 20+(5 x 2/5 )+ 3 show your work

When turned about its axis of rotation, which shape could have created this three-dimensional object?

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%