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.
2008 launch of the SM-3 missile used to destroy American spy satellite USA-193
The 2012 U.S. presidential campaign rang with “get tough” cries to end Iran’s nuclear capacity and c
Basic molecular mechanisms of delayed-type hypersensitivity.
Structure of a complex of a type II DNA methylase with DNA
Rock Type Influences Weathering
The DNA of S-type bacteria can transform R-type bacteria into the same S type.