Identify the constants

What is the y intercept of f(x)=(1/2)^x?

Find the area of a parallelogram with the given vertices. p(-2, -5), q(9, -5), r(1, 5), s(12, 5)

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)?