How can you use an equivalent form of the percent proportion to solve a percent problem?

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?

State if the two triangles are congruent. if they are, state how you know?

Icould really use some with this question.