(Solution Document) 1. A survey of 95 families showed that 40 of the families owned at least one tv.

1. A survey of 95 families showed that 40 of the families owned at least one tv.

a)Suppose you reduce your level of confidence to 90%. Will this create a wider or narrower interval? Does this mean that precision will increase or decrease?

2.A survey of shoppers is planned to see what percentage use credit cards. Prior surveys suggest 53% of shoppers use credit cards. How many randomly selected shoppers must we survey in order to estimate the proportion of shoppers who use credit cards to within 3% with 95% confidence?