Answer Happy

m. Assume that the zinc mass for the population of AAA batteries is normally distributed. A researcher has constructed a 90% confidence interval about the population mean zinc mass in grams using a random sample of 100 AAA batteries. The resulting confidence interval is between 2.05 grams and 2.09 grams. Which of the following statements is TRUE? (1) There is a 90% probability that the true population mean zinc mass for AAA batteries is between 2.05 grams and 2.09 grams. (2) 90% of the population of AAA batteries has the average between 2.05 grams and 2.09 grams. (3) Based on the resulting confidence interval, the population mean is 2.07 grams. (4) Based on the resulting confidence interval, the margin of error is 0.02 grams. (5) All of the above n. Assume that the population distribution of zinc mass for AAA batteries is unknown, but its standard deviation is known as 0.03 grams according to one study. A researcher has collected a random sample of 100 AAA batteries and the sample mean zin mass for 100 AAA batteries was 2 grams. If the researcher wants to construct a 95% confidence interval for the population mean zinc mass for AAA batteries, which of the following statements is TRUE? (1) Since the population distribution is unknown, we can't construct the confidence interval. (2) The standard error of the mean is 0.03 grams. (3) The critical value for the 95% confidence interval is 1.645. (4) If the researcher collects more sample than 100 AAA batteries, then the resulting confi- dence interval will become wider. (5) None of the above