Answer:
e) None of the above.
Step-by-step explanation:
a) The sample mean is an unbiased estimate of the population mean.
False. Population mean can be estimated with a margin of error around the sample mean in a specified confidence level
b) The z-critical value is an estimate of the population mean.
False. z value is a conversion of values in standard normal distribution
c) The t-critical value is an estimate of the population standard deviation.
False. Similar to z-score t-value is a conversion in t-distribution.
d) The sample standard deviation is an unbiased estimate of the population standard deviation
False. It is a biased estimate.