Question: Refer to Exercise. Calculate an 80% confidence interval that estimates the proportion of U.S. families with children that always has the television on when they eat dinner as a family.

Exercise: In a Gallup poll done in 2007, a randomly selected sample of n = 254 U.S. parents was asked how often the television was on when they ate dinner as a family. About 33% of the sample said "always" (Source: www.pollingreport.com/ life.htm).

a. Calculate the standard error of the sample proportion.

b. Calculate a 95% confidence interval that estimates the proportion of U.S. families with children who always have the television on when they eat dinner as a family.

c. Calculate a 90% confidence interval for this situation.

d. Write a sentence that interprets the confidence interval found in part (c).