According to a recent survey of 1200 people, 61% feel that the president is doing an acceptable job. We are interested in the population proportion of people who feel the president is doing an acceptable job.
Define the Random Variables
and
, in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 90% confidence interval for the population proportion of people who feel the president is doing an acceptable job.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
CI: (0.59, 0.63)
EB = 0.02
A survey of the mean amount of cents off that coupons give was done by randomly surveying one coupon per page from the coupon sections of a recent San Jose Mercury News. The following data were collected: 20¢; 75¢; 50¢; 65¢; 30¢; 55¢; 40¢; 40¢; 30¢; 55¢; $1.50; 40¢; 65¢; 40¢. Assume the underlying distribution is approximately normal.
Define the Random Variables
and
, in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 95% confidence interval for the population mean worth of coupons.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
If many random samples were taken of size 14, what percent of the confident intervals constructed should contain the population mean worth of coupons? Explain why.
An article regarding interracial dating and marriage recently appeared in the
Washington Post . Of the 1709 randomly selected adults, 315 identified themselves as Latinos, 323 identified themselves as blacks, 254 identified themselves as Asians, and 779 identified themselves as whites. In this survey, 86% of blacks said that their families would welcome a white person into their families. Among Asians, 77% would welcome a white person into their families, 71% would welcome a Latino, and 66% would welcome a black person.
We are interested in finding the 95% confidence interval for the percent of all black families that would welcome a white person into their families. Define the Random Variables
and
, in words.
Which distribution should you use for this problem? Explain your choice.