8)In a recent year, the Better Business Bureau settled 75% of complaints they received. (Source: USA Today, March 2, 2009) You have been hired by the Bureau to investigate complaints this year involving computer stores. You plan to select a random sample of complaints to estimate the proportion of complaints the Bureau is able to settle. Assume the population proportion of complaints settled for the computer stores is the 0.75, as mentioned above. Suppose your sample size is 219. What is the probability that the sample proportion will be at least 2 percentage points higher than the population proportion?

9)In a recent year, the Better Business Bureau settled 75% of complaints they received. (Source: USA Today, March 2, 2009) You have been hired by the Bureau to investigate complaints this year involving computer stores. You plan to select a random sample of complaints to estimate the proportion of complaints the Bureau is able to settle. Assume the population proportion of complaints settled for the computer stores is the 0.75, as mentioned above. Suppose your sample size is 178. What is the probability that the sample proportion will be within 10 percentage points of the population proportion?

10)A Food Marketing Institute found that 27% of households spend more than $125 a week on groceries. Assume the population proportion is 0.27 and a simple random sample of 134 households is selected from the population. What is the probability that the sample proportion of households spending more than $125 a week is between 0.22 and 0.42?

11)A population of values has a normal distribution with =35.7=35.7 and =64=64. You intend to draw a random sample of size n=243n=243. What is the mean of the distribution of sample means? What is the standard deviation of the distribution of sample means?

12)Let XX represent the full height of a certain species of tree. Assume that XX has a normal probability distribution with =10.8=10.8 ft and =5.4=5.4 ft. You intend to measure a random sample of n=204n=204trees. What is the mean of the distribution of sample means? What is the standard deviation of the distribution of sample means (i.e., the standard error in estimating the mean)?

13)A population of values has a normal distribution with =248=248 and =63=63. You intend to draw a random sample of size n=46n=46.

Find the probability that a single randomly selected value is greater than 252.6. P(X > 252.6) = Enter your answers as numbers accurate to 4 decimal places.

Find the probability that a sample of size n=46n=46 is randomly selected with a mean greater than 252.6.