What are the 10th and 90th percentiles of the distribution of sample proportion for the population proportion below?

People end up tossing 12% of what they buy at the grocery store (Reader’s Digest, March 2009). Assume this is the true population proportion and that you plan to take a sample survey of 100 grocery shoppers to further investigate their behavior.

The 10th percentile is 0.0784.

The 90th percentile is 0.1616.

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 a proportion p in a sample of size n, we have that

In this problem, we have that:

10th percentile:

X when Z has a pvalue of 0.1. So X when Z = -1.28.

The 10th percentile is 0.0784.

90th percentile:

X when Z has a pvalue of 0.9. So X when Z = 1.28.

The 90th percentile is 0.1616.

step-by-step explanation: examine the two-step equation.

−  

7

4

+  

x

4

= 2

which property of operations allows you to add the same constant term to both sides?

multiplication property of equality

division property of equality

addition property of equality

subtraction property of equality

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this