Question 9 (1 point) The standard deviation of the sample mean is equal to 1) The population variance 2) The sample variance 3) The sample error 4) Question 10 (1 point) A local retail company found a sample mean of $1,000 using a sample size of 100. What is the 90% confidence level for the estimated mean if the estimated standard deviation of $20? Assume the t value is 1.65. 1) $996.7 to $1,003.3 2) $992.5 to $1,008.5 3) $1,000.0 to $1,006.6 4) $996.0 to $1,004.0