A Food Marketing Institute found that 32% of households spend
more than $125 a week on groceries. Assume the population
proportion is 0.32 and a simple random sample of 357 households is
selected from the population. What is the probability that the
sample proportion of households spending more than $125 a week is
less than 0.31?
Note: You should carefully round any z-values you calculate to
4 decimal places to match wamap's approach and calculations.