Hello I'm new at statistics. I am in a need of help here. I'm sorry I can't understand the practice example work. It would be nice to have a one on one tourting session so someone can help me understand this. I need help learning confidence intervals. I'm new to this and I would like to get educated on this topic. Thank you for helping me learn this.

Confidence Interval.

Confidence Intervals for the Mean sigma known.

Put alpha = .05 and give the values for the problem.

Assuming .05 as your alpha value, make up a problem similar to this one. Make up 36 gas prices for example. Use price values in your list that's made up and be sure they are similar to the prices you have had in your area.List the values

attach the excel spreadsheet

Example below:

• Locate the mean. List all 36 gas prices in cells A1 to A36 in your excel spreadsheet.
• On a different cell type in =average(A1:A36) and the hit enter to put the average
• Assume your answer is 2.65
• On a different cell type in=stdev.s(A1:A36)or =stdevA(A1:A36) and enter to put the standard deviation
• Assume your answer is .43
• Then put this in an excel cell=confidence.norm(.05,.43,36)and hit enter. This is the E value
• So take the mean of 2.65 and we have(2.65-E, 2.65+E) for your confidence interval

Formula we used above for the confidence interval:

The formula is E= zsubc * sigma / sqrt n

Where the left hand endpoint is xbar - E and the right hand endpoint is xbar + E