1-If in a sampling distribution of the sample size is 25, what assumption must hold for the
sampling distribution of to be normal? (Points : 1)
Population distribution is normal.
Population distribution is uniform
4. If the population proportion is .4 with a sample size of 20, then is this sample large enough so
that the sampling distribution of is a normal distribution. (Points : 1)
True
False
6. Whenever the sampled population has a normal distribution, the sampling distribution of is a
normal distribution for (Points : 1)
only large sample sizes.
only small sample sizes.
any sample size.
only samples of size 30 or more.
7. When the population is normally distributed and population standard deviation ? is unknown,
then for any sample size n, the sampling distribution of is a t distribution. (Points : 1)
True
False
8. When the sample size and sample standard deviation remain the same, a 99% confidence
interval for a population mean, µ will be _____ the 95% confidence interval for µ. (Points : 1)
wider than
narrower than
equal to
10. When the level of confidence and sample proportion remain the same, a confidence interval
for a population proportion p based on a sample of n = 100 will be _____ a confidence interval
for p based on a sample of n = 400. (Points : 1)
wider than
narrower than
equal to

Solution
1) Population distribution is normal.
4) 0.4*20=8>5, true
6) only samples of size 30 or more.
7) True
8) wider than
10) wider than