Confidence Interval...I found the interval in the problem now the next question is...?

Question

"From the confidence interval do you believe that the claim is true?"
Here is the origional question
"A claim was made that the average score on the ACT Test for student sat Jefferson College was 19 with a standard deviation of 3. A sample of 81 students had an average score of 17.8. Find a 95% confidence interval about the true mean. From the confidence interval do you believe that the claim is true?"

I got 17.58

Answer 1

I haven't checked your math to see if the interval is correct, but all you have to do is compare your range to the claimed average. If the claim fits with the range the sample produced, then you would probably agree that that average fits. If the claim is outside, then based on your sample results, you would probably conclude that the claim is false.

Answer 2

It's been a while since my statistics days. But it's fairly obvious that it's hard to believe the claim, since there is a 95% chance that the average is between 17.58 and 18.018. If I was making that claim, I would triple check my calculations if I knew a sample of 81 students only received an average of 17.8.

Answer 3

i think of this could be a z era... yet in any case right that's the kind you try this. i take advantage of a calculator in case you dont, you will probable choose it, its helps! in any case, right that's the equation: (x bar) +/- (z*) x (common deviation) xbar is ninety 4 (the flexibility +/- a million.sixty 4 x $10 you in addition to mght ought to fulfill the standards to do this nonetheless... i desire a random pattern...which we are able to assume and we desire a classic inhabitants...that would additionally be assumed. you are able to kind in this equation on your calculator (or do it by ability of hand, in case you have a graphing calculator, press stat attempt z era and enter interior the stats), and additionally you gets larger cut back $ninety seven.267 decrease cut back $ninety.733 they might discover the money for the vehicle!