Explain why every year must contain at least one Friday the 13th.

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Determine the relationship of ab and cd given the following points

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)?