Use the table to answer the question.

Based upon a smaller sample of only 170 st. paulites, what is the probability that the sample proportion will be within of the p

Pepsi [2]

Given that in 2008 the Better Business Bureau settled 75% of complaints they received (USA Today, March 2, 2009). Suppose you have been hired by the Better Business Bureau to investigate the complaints they received this year involving new car dealers. You plan to select a sample of new car dealer complaints to estimate the proportion of complaints the Better Business Bureau is able to settle. Assume the population proportion of complaints settled for new car dealers is .75, the same as the overall proportion of complaints settled in 2008.

Part a) :

Suppose you select a sample of 450 complaints involving new car dealers. Show the sampling distribution of (to 4 decimals).

Population proportion = 0.75
sample size. n = 450
$Standard\ error=\sqrt{\frac{p(1-p)}{n}} \\ \\ =\sqrt{\frac{(0.75)(0.25)}{450}} = 0.0204$

Therefore, the sampling distribution has a proportion of 0.75 and a standard error of 0.0204.

Part b) :

Based upon a sample of 450 complaints, what is the probability that the sample proportion will be within .04 of the population proportion (to 4 decimals)?

The probability that the sample proportion will be within 0.04 of the population proportion is given by:

$P(p\ \textless \ 0.75\pm0.04)=2P\left(z\ \textless \ \frac{0.04}{0.0204} \right)-1 \\ \\ 2P(z\ \textless \ 1.961)-1=2(0.97505)-1=1.9501-1 \\ \\ =\bold{0.9501}$

Therefore, the probability that the sample proportion will be within .04 of the population proportion is 0.9501.

Part C:

Suppose you select a sample of 200 complaints involving new car dealers. Show the sampling distribution of (to 4 decimals).

Population proportion = 0.75
sample size. n = 200
$Standard\ error=\sqrt{\frac{p(1-p)}{n}} \\ \\ =\sqrt{\frac{(0.75)(0.25)}{200}} = 0.0306$

Therefore, the sampling distribution has a proportion of 0.75 and a standard error of 0.0306.

Part D):

Based upon the smaller sample of only 200 complaints, what is the probability that the sample proportion will be within .04 of the population proportion (to 4 decimals)?


The probability that the sample proportion will be within 0.04 of the population proportion is given by:

$P(p\
 \textless \ 0.75\pm0.04)=2P\left(z\ \textless \ \frac{0.04}{0.0306} 
\right)-1 \\ \\ 2P(z\ \textless \ 1.306)-1=2(0.90429)-1=1.80858-1 \\ \\
 =\bold{0.8086}$

Therefore, the probability that the sample proportion will be within .04 of the population proportion is 0.8086.

8 0

3 years ago

PLEASE HELP ME I BEG YOU PLEASE PLEA PLEASE

goldenfox [79]

The first one is the first one
The second one is the fourth one
The third one is the third one
The fourth one is the second one
The fifth one is the third one
The sixth one is the second one

8 0

3 years ago

Bao is mixing flour and water to make dough the graph shows how much water he uses for different amounts of flour .How many lite

Allushta [10]

To know how many liters of water Bao use per liter of flour we have to divide the liters or flour so: