Which of the following is NOT true about a standard normal distribution?

• The mean is 0 and the standard deviation is -1
• The mean is 0 and the standard deviation is 1
• It is symmetrical about the mean
• All of the above are true

Which of the following is true about the sampling distribution of a mean?

• The distribution is non-symmetrical
• It is normally distributed
• It is left skewed
• It is right skewed

We conduct a one-sample z-test to compare a population mean to the reference population when the ________________ is known.

• sample standard deviation
• sample mean
• population mean
• population standard deviation

Which of the following correctly describes the relationship between the standard normal (z) and the t distribution?

• The standard normal is an approximation to the t distribution
• As the degrees of freedom increase, the t distribution approaches the standard normal
• As the degrees of freedom decrease, the t distribution approaches the standard normal
• The t distribution is the inverse operation of the standard normal

Increasing the sample size decreases the margin of error.

• True or False?

Increasing the confidence level decreases the margin of error?

• True or False?