(Solved): The proper operation of typical home appliances requires voltage levels that do not vary much. Lis ...

The proper operation of typical home appliances requires voltage levels that do not vary much. Listed below are 9 voltage levels (in volts) at a random house on 9 different days. 120.2 119.9 120.1 119.8 120.1 120.1 119.8 119.8 120 The mean of the data set is 119.98; the sample standard deviation is 0.156; if the normality plot is not provided you may assume that the voltages are normally distributed. Construct a 90% confidence interval for the variance (standard deviation) of all voltages in the house. i. Procedure: One variance x² procedure ii. Assumptions: (select everything that applies) Population standard deviation is known Sample size is greater than 30 Normal population ?Simple random sample ? Population standard deviation is unknown The number of positive and negative responses are both greater than 10 iii. Unknown parameter: o², population variance ? iv. Point estimate: sample variance, s² v. Confidence level % and a = ? a and 1 2 2 o Critical values: (Round the answer to 3 decimal places) ? left= right= O also (Round the answer to 3 decimal places) Part 2 of 5