Please help with this math

Anyone know? is appreciated! will mark brainliest if correct!

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)?

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin.how many doctors use brand x aspirin