Question

URGENT!!!

Answer 1

A field test for a new exam was given to randomly selected seniors. The exams were graded, and the sample mean and sample standard deviation were calculated. Based on the results, the exam creator claims that on the same exam, nine times out of ten, seniors will have an average score within 6% of 80%.

Answer 2

Is the confidence interval at 90%, 95%, or 99%? What is the margin of error? Calculate the confidence interval and explain what it means in terms of the situation.

Answer 3

@mathmate @ganeshie8 Help?

Answer 4

`nine times out of ten`

is how much confidence ?

Answer 5

90%

Answer 6

Good. I have just seen your work. One sec

Answer 7

Ok. (:

Answer 8

Margin of error is not 6℅

Answer 9

Ugh! Is it 36%?

Answer 10

That's another answer I got but it didn't see right to me.

Answer 11

Nope. Margin of error is 6% of 80℅

Answer 12

What is 6% of 80?

Answer 13

4.8%?

Answer 14

Yep
that is the margin of error here

Answer 15

Ok. What about the last part of the problem?

Answer 16

As the name says, confidence interval is just an interval of form (a, b)

Answer 17

No

Answer 18

How would I get the correct answer?

Answer 19

You need to calculate the interval

Answer 20

...how

Answer 21

to get the lower value subtract margin of error from the mean

Answer 22

80 - 4.8 = ?

Answer 23

Oh! 75.2%?

Answer 24

You can guess how to get the upper value

Answer 25

simply add the margin of error to the mean

Answer 26

Add 4.8?

Answer 27

Oo ok!