Practice Final Exam MULTIPLE CHOICE

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. Which of the following statement is true? 1) _______ A) The sampling distribution for the sample mean follows the t-distribution with 15 degrees of freedom. B) The mean of the sampling distribution for the sample mean is 14.8 feet. C) The sampling distribution for the sample mean follows the t-distribution with 16 degrees of freedom. D) The standard error is 0.65 feet. E) The sampling distribution for the sample mean is Normal with a mean of 14.8 feet and standard deviation of 0.65 feet. 2) In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. The standard error of the mean is 2) _______ A) 0.1625 ft. B) 0.346 ft. C) 1.625 ft. D) 0.0098 ft. E) 0.65 ft. 3) In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist collects a random sample of 15 rods and finds the sample mean length to be 14.8 feet and a standard deviation of 0.65 feet. The 95% confidence interval for the true mean length of rods produced by this process is 3) _______ A) 13.912 to 15.688 ft. B) 14.544 to 15.056 ft. C) 13.834 to 15.766 ft. D) 14.345 to 15.255 ft. E) 14.440 to 15.160 ft. 4) A manufacturer of cheese filled ravioli supplies a pizza restaurant chain. Based on data collected from its automatic filling process, the amount of cheese inserted into the ravioli is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 ravioli. The correct value of t to construct a 98% confidence interval for the true mean amount of cheese filling is 4) _______ A) 2.064 B) 3.467 C) 3.745 D) 2.492 E) 2.797 5) A manufacturer of cheese filled ravioli supplies a pizza restaurant chain. Based on data collected from its automatic filling process, the amount of cheese inserted into the ravioli is normally distributed. To make sure that the automatic filling process is on target, quality control inspectors take a sample of 25 ravioli and measure the weight of cheese filling. They find a sample mean weight of 15 grams with a standard deviation of 1.5 grams. What is the margin of error at 90% confidence? 5) _______ A) 0.5133 grams B) 0.06 grams C) 1.5 grams D) 0.3 grams E) 0.8391 grams 6) A pharmaceutical company wants to answer the question whether it takes longer than 45 seconds for a drug in pill form to dissolve in the gastric juices of the stomach. A sample was taken from patients taken the given drug in pill form and times for the pills to be dissolved were measured. State the hypotheses to test this question. 6) _______