Every confidence interval has associated z value. As confidence interval increases so do the z value associated with it.
The confidence interval can be calculated using following formula:

Where

is the mean value, z is the associated z value, s is the standard deviation and n is the number of samples.
We know that standard deviation is simply a square root of variance:

The confidence interval of 95% has associated z value of <span>1.960.
</span>Now we can calculate the confidence interval for our income:
I assume that the numbers are: 4,4,6,1,5,2,6
If so, then the MAD is 1.43
To find the MAD, you first find the mean of the list. It is 4.
Then find the absolute difference of each number from the mean.
Those values are: 0,0,2,3,1,2,2
Now find the mean of those numbers and you have about: 1.43
Answer:
D) Kaia saved $165.45 on a new guitar because it was 75 percent off. The price of the guitar before the discount was $220.60.
Step-by-step explanation:
Given in the attached diagram shows a model of a discount given on a purchase of guitar showing 75% of the price of guitar ($55.15 + $55.15 + $55.15) that was given.
It also tells that the price pays is 25% of the price of the guitar before the discount. I.e. 25% of %220.60 = 0.25 × 220.60 = $55.15.
From the diagram given, we can infer that Kaia bought the guitar at $55.15 while saving $165.45. That is 25% of the original price. And the amount saved, $165.45, is %75 of the original price ($55.15+$55.15+$55.15).
The answer is D.
First divide 228 miles by 6 hours and u get 38 miles per hour
next, divide 285 miles by 38 miles and u get 15/2 or 7.5 hours
the answer is 7 and a half hours
hope this helps! good luck!