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and that the wafers are independent; that is, the probability that a wafer contains a large
particle is not dependent on the characteristics of any of the other wafers. If 15 wafers are
analyzed, what is the probability that no large particles are found?
Are the means significantly different at the 5% level?
a.A statistics practitioner would like to estimate a population mean to within 10 units. The con- fidence level has been set at 95% and σ = 200. Determine the sample size.
b. Suppose that the sample mean was calculated as 500. Estimate the population mean with 95% confidence.
a. From the information given here determine the 95% confidence interval estimate of the population mean.
x = 100 = 20 n = 25
b. Repeat part (a) with x = 200.
c. Repeat part (a) with x = 500.
d. Describe what happens to the width of the confidence interval estimate when the sample mean increases.
95% confidence interval estimate of the population
mean.
x = 100 = 20 n = 25
b. Repeat part (a) with x = 200.
c. Repeat part (a) with x = 500.
d. Describe what happens to the width of the confidence
interval estimate when the sample mean
increases.
a. A statistics practitioner randomly sampled 100 observations from a population with a standard deviation of 5 and found that x is 10. Estimate the population mean with 90% confidence.
b. Repeat part (a) with a sample size of 25.
c. Repeat part (a) with a sample size of 10.
d. Describe what happens to the confidence interval estimate when the sample size decreases.
4. A buyer of electric bulbs purchases 400 bulbs; 200 bulbs of each brand. Upon testing these bulbs be found that brand A has an average of 1225 hrs with a S.D of 42 hrs.
Where as brand B had a mean life of 1265 hrs with a S.D of 60hrs. Can the buyer be certain that brands B is superior than brand A in equality
a. Obtain the point estimate for the proportion of all ColourSmart television sets that have lasted at least five years without needing a single repair. *
b. Determine whether the condition is satisfied to use the large sample formula of the confidence interval of the population proportion. (Check the assumption to use Z distribution) *
c. Find a 99% confidence interval for the true proportion of all ColourSmart television sets that have lasted at least five years without needing a single repair. (Type your answer in this format: Margin error =___x ____ =____; 99% CI = __________ <___<_____ ) *
4. A buyer of electric bulbs purchases 400 bulbs; 200 bulbs of each brand. Upon testing these bulbs be found that brand A has an average of 1225 hrs with a S.D of 42 hrs.
Whereas brand B had a mean life of 1265 hrs with a S.D of 60hrs. Can the buyer be certain that brands B is superior than brand A in equality
#340153 on Dec 2023