You scored 88, 92, and 87 on three tests. write and solve an equation to fi nd the score you need on the fourth test so that your mean test score is 90.

The birth weights of newborn babies in the unites states follow in a normal distrubution with a mean of 3.4 kg and standard deviation of 0.6 kg. reaserches interested in studying how. children gain weights decide to take random samples of 100 newborn babies and calculate the sample mean birth weights for each sample