8.17 Consumer Confidence An increase in the rate of consumer savings is frequently tied to a lack of con- fidence in the economy and is said to be an indicator of a recessional tendency in the economy. A random sampling of n 200 savings accounts in a local com- munity showed a mean increase in savings account val- ues of 7.2% over the past 12 months, with a standard deviation of 5.6%. Estimate the mean percent increase in savings account values over the past 12 months for depositors in the community. Find the margin of error for your estimate.