Question

2)According to a 2009 Reader's Digest article, people throw away about 12% of what they buy at the grocery store. Assume this is the true proportion and you plan to randomly survey 68 grocery shoppers to investigate their behavior. What is the probability that the sample proportion does not exceed 0.18?

Note: You should keep at least 4 decimal places for any intermediate calculations you make to match wamap's approach and calculations.

Answer =  (Enter your answer as a number accurate to 4 decimal places.)

3)Based on historical data, your manager believes that 33% of the company's orders come from first-time customers. A random sample of 198 orders will be used to estimate the proportion of first-time-customers. What is the probability that the sample proportion is greater than than 0.23?

Note: You should carefully round any z-values you calculate to 4 decimal places to match wamap's approach and calculations.

Answer =  (Enter your answer as a number accurate to 4 decimal places.)

4)According to a 2009 Reader's Digest article, people throw away approximately 12% of what they buy at the grocery store. Assume this is the true proportion and you plan to randomly survey 61 grocery shoppers to investigate their behavior. What is the probability that the sample proportion exceeds 0.09?

Note: You should carefully round any z-values you calculate to 4 decimal places to match wamap's approach and calculations.

Answer =  (Enter your answer as a number accurate to 4 decimal places.)

5)Based on historical data, your manager believes that 32% of the company's orders come from first-time customers. A random sample of 225 orders will be used to estimate the proportion of first-time-customers. What is the probability that the sample proportion is between 0.21 and 0.46?

Note: You should carefully round any z-values you may calculate to 4 decimal places to match wamap's approach and calculations.

Answer =  (Enter your answer as a number accurate to 4 decimal places.)

6)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 129. What is the probability that the sample proportion will be within 10 percentage points of the population proportion?

Note: You should carefully round any z-values you calculate to 4 decimal places to match wamap's approach and calculations.

Answer =  (Enter your answer as a number accurate to 4 decimal places.)

7)A population of values has a normal distribution with μ=204.9μ=204.9 and σ=81.9σ=81.9. You intend to draw a random sample of size n=222n=222.

What is the mean of the distribution of sample means?
μ¯x=μx¯=  (Enter your answer as a number accurate to 4 decimal places.)

What is the standard deviation of the distribution of sample means?
(Report answer accurate to 4 decimal places.)
σ¯x=σx¯=

8)Let XX represent the full height of a certain species of tree. Assume that XX has a normal probability distribution with μ=75.9μ=75.9 ft and σ=9.6σ=9.6 ft.

You intend to measure a random sample of n=181n=181 trees.

What is the mean of the distribution of sample means?
μ¯x=μx¯=

What is the standard deviation of the distribution of sample means (i.e., the standard error in estimating the mean)?
(Report answer accurate to 4 decimal places.)
σ¯x=σx¯=

9)

A population of values has a normal distribution with μ=135.7μ=135.7 and σ=88σ=88. You intend to draw a random sample of size n=59n=59.

Find the probability that a single randomly selected value is greater than 117.4.
P(X > 117.4) =

Find the probability that a sample of size n=59n=59 is randomly selected with a mean greater than 117.4.
P(¯xx¯ > 117.4) =  Enter your answers as numbers accurate to 4 decimal places.

10)A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 261.5-cm and a standard deviation of 0.5-cm. For shipment, 13 steel rods are bundled together.

Find the probability that the average length of a randomly selected bundle of steel rods is less than 261.7-cm.
P(¯xx¯ < 261.7-cm) =

Enter your answer as a number accurate to 4 decimal places.

Answer 1