Question 1
A marketing research company is estimating which of two soft drinks college students prefer. A random sample of 341 college students produced the following 95% confidence interval for the proportion of college students who prefer one of the colas:
What additional assumptions are necessary for the interval to be valid?
◦ The sample was randomly selected from an approximately normal population.
◦ No additional assumptions are necessary.
◦ The sample proportion equals the population proportion.
◦ The population proportion has an approximately normal distribution.
Question 2
What type of car is more popular among college students, American or foreign? One hundred fifty-nine college students were randomly sampled and each was asked which type of car he or she prefers. A computer package was used to generate the printout below for the proportion of college students who prefer American automobiles.
SAMPLE PROPORTION = .396226
SAMPLE SIZE = 159
UPPER LIMIT = .46418
LOWER LIMIT = .331125
Is the sample large enough for the interval to be valid?
◦ No, the population of college students is not normally distributed.
◦ Yes, since
n
and
n
are both greater than 15.
◦ No, the sample size should be at 10% of the population.
◦ Yes, since
n > 30.
Type C killer whales in the Ross Sea. The eye patch slants forward.
A family of African Americans arrive in Chicago, migrants from the American South, in an exodus that
Faith Ringgold, God Bless America, No. 13 from the series American People.
Basic molecular mechanisms of delayed-type hypersensitivity.
Patterns of North American Religion