The following data represent the muzzle velocity (in feet per second) of rounds fired from a 155-mm gun. For each round, two
measurements of the velocity were recorded using two different measuring devices, resulting in the following data. Complete parts (a) through (d) below. Observation 1 2 3 4 5 6
A 794.4 791.1 794.9 790.2 790.1 790.9
B 795.7 786.4 796.6 788.7 798.0 787.1
a. Why are these matched-pairs data?
b. Is there a difference in the measurement of the muzzle velocity between device A and device B at α=0.01
c. Construct a 99% confidence interval about the population mean difference. Compute the difference as device A minus device B. Interpret your results.
A. Two measurements(AandB)are taken on the same round.\oIs there a difference in the measurement of the muzzle velocity between device A and device B at the α=0.01 level of significance? Note: A normal probability plot and boxplot of the data indicate that the differences are approximately normally distributed with no outliers.
B. Construct a 99% confidence interval about the population mean difference. Compute the difference as device A minus device B. Interpret your results. The confidence interval is (__,__)?
Answer:
Open chart in StatCrunch --- Stat --- T Stats --- Paired --- Enter values: Sample 1 = A, Sample 2 = B --- Click on Confidence Interval… and enter Level which is my #%. --- Compute
Because when we want to change decimal as percents we need to replace the period on the left side 2 times. But when we want to change percent as a decimal, then we need to move the period 2 times on the right.
