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Home-Work-Chapter-13 1)  A survey of 95 families showed that 40 of the families owned at least one tv

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Home-Work-Chapter-13

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

1. (2 points) Find the 90% confidence interval on the proportion of families who own at least one tv.
2. (1 points) Find the Margin of Error associated with this confidence interval.
3. (1 points) Interpret this interval in the context of the problem.  Carefully explain what 90% confidence means in this context.
4. (1 points) Suppose you reduce your level of confidence to 80%. Will this create a wider or narrower interval?  Does this mean that precision will increase or decrease? 

2. (5 points)  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?
3. (5 points) Based on past experience, a bank believes that 7% of the people who receive loans will not make payments on time. The bank has recently approved 200 loans. Describe the sampling distribution. What is the probability that over 11% of these clients will not make timely payments?