Chapter 6 Assignment Name: 1) 13] Construct a 90% confidence interval for the population mean, u. Assume the population has a normal distribution. A random sample of 20 fluorescent light bulbs has a mean life of 640 hours with a standard deviation of 36 hours Find the margin of error, E. construct the interval, and interpret your interval in words 2) [2] A random sample of 14 parking meters in a beach community showed the following incomes for a day. Assume the incomes are normally distributed. $3.65 $4.15 $2.70 $5.30 $2.60 $5.25 $6.75 $4.25 $7.00 $3.00 $3.30 $6.20 $3.50 $2.75 Find the 90% confidence interval for the true mean. Interpret the interval in words. 3) [1] When 450 college students were surveyed,160 said they own their car. Find a point estimate for p, the population proportion of students who own their cars. P 4) 121 When 487 college students were surveyed, 120 said they own their car. Construct a 99% confidence interval for the proportion of college students who say they own their cars. Interpret the interval in words. 5) [2] A private opinion poll is conducted for a politician to determine what proportion of the population favors decriminalizing marijuana possession. How large a sample is needed in order to be 90% confident that the sample proportion will not differ from the true proportion by more than 3%? n p q (ze