Answer:
70
Step-by-step explanation:
11.p=-8, 17-8=9
12.y=11, 3*11=33+16=46
13.t=4, 4*4=16-14=2
14.x=9, -9x 9*8=82-9=72-9=62
15.z=4, 12*4=48-18=30
16.g=0, 4*0=0, 7+0=7
17.x=4, 9*4=36-24=-3
18.q=3, 18*3=48+2=50
19.c=2, 3*2=6-4.5=4.1
20.y=4, 9+4=13+4.8=17.4
Using the <u>normal distribution and the central limit theorem</u>, it is found that there is a 0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.
In a normal distribution with mean
and standard deviation
, the z-score of a measure X is given by:

- It measures how many standard deviations the measure is from the mean.
- After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.
- By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportions has mean
and standard error 
In this problem:
- Sample of 500 customers, hence
.
- Amazon believes that the proportion is of 70%, hence

The <u>mean and the standard error</u> are given by:


The probability is the <u>p-value of Z when X = 0.68</u>, hence:

By the Central Limit Theorem



has a p-value of 0.1635.
0.1635 = 16.35% probability of a sample result with 68% or fewer returns prior to the third day.
A similar problem is given at brainly.com/question/25735688
This is considered a function because each input has a different output. For example, a certain x value doesnt equal 2 different y values, making this a function. Take this: if there is (2,4) and (3,4), this is a function because although the y values are the same, the x values are different. (2,3) and (2,4) do not convey a function because the x values are the same, but each has a different y value.
hope this helped!!!
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