According to a study done by the Gallup organization, the proportion of Americans who are satisfied with the way things are going in their lives is 0.82. In a sample of 100 Americans, what is the probability that the proportion who are satisfied with the way that things are going in their life exceeds 0.85

21.77% probability that the proportion who are satisfied with the way that things are going in their life exceeds 0.85

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean and standard deviation , the zscore of a measure X is given by:

The Z-score 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. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

For proportions p in a sample of size n, we have that

In this problem:

In a sample of 100 Americans, what is the probability that the proportion who are satisfied with the way that things are going in their life exceeds 0.85

This is 1 subtracted by the pvalue of Z when X = 0.85. So

has a pvalue of 0.7823

1 - 0.7823 = 0.2177

21.77% probability that the proportion who are satisfied with the way that things are going in their life exceeds 0.85

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3

thats one

step-by-step explanation: