The Food Marketing Institute shows that 15% of households spend more than $100 per week on groceries. Assume the population proportion is p = 0.15 and a sample of 800 households will be selected from the population. Use z-table.

a- Calculate (), the standard error of the proportion of households spending more than $100 per week on groceries (to 4 decimals).

b- What is the probability that the sample proportion will be within +/- 0.02 of the population proportion (to 4 decimals)?

c- What is the probability that the sample proportion will be within +/- 0.02 of the population proportion for a sample of 1,300 households (to 4 decimals)?