A sample of size 12 is taken from a population that is ...

[NguyenJ]

A sample of size 12 is taken from a population that is symmetrical and mounded. A sample mean of 16.2 is obtained and used to construct a 90 confidence interval for the population mean with an unknown . What is the value of the appropriate confidence coefficient?
  1.1.80
  2.1.65
  3.1.28
  4.1.36

Question 2

The t-distribution is more appropriate than the
   z-distribution when the ________ is unknown. The unknown parameter will than be estimated with the ________.

  1. sample size, sample mean
  2. population standard deviation, sample standard deviation
  3. df, population mean
  4. point estimate, sample mean

[Amiracle]

Answer to Question 1

1

Answer to Question 2

2

[NguyenJ]

Excellent

[Liddy]

Thanks for the timely response, appreciate it