A standardized test has been conducted to compute the compressive strength of two brands of cements. Fourteen cubes of cement 1 were tested by crushing them under a hydraulic press. Fifteen cubes of cement 2 were tested under similar condition. The cubes of cement 1 gave an average compressive strength of 59.4 MPa with a sample standard deviation of 7.8 MPa, while the cubes of cement 2 gave an average of 55.8 MPa with a sample standard deviation of 8.2 MPa. Can we conclude at the 0.05 level of significance that the compressive strength of cement 1 exceeds that of cement 2 by more than 2 MPa? Assume the populations to be approximately normal with equal variances. a. What is the statistic/type of hypothesis testing to be used in this problem? b. What is the null and alternative hypothesis c. What are the significance level and the type of test? d. What is the critical value e.What is the standardized test statistic? f. What is the statistical decision in statement form?
A standardized test has been conducted to compute the compressive strength of two brands of cements. Fourteen cubes of cement 1 were tested by crushing them under a hydraulic press. Fifteen cubes of cement 2 were tested under similar condition. The cubes of cement 1 gave an average compressive strength of 59.4 MPa with a sample standard deviation of 7.8 MPa, while the cubes of cement 2 gave an average of 55.8 MPa with a sample standard deviation of 8.2 MPa. Can we conclude at the 0.05 level of significance that the compressive strength of cement 1 exceeds that of cement 2 by more than 2 MPa? Assume the populations to be approximately normal with equal variances.
a. What is the statistic/type of hypothesis testing to be used in this problem?
b. What is the null and alternative hypothesis
c. What are the significance level and the type of test?
d. What is the critical value
e.What is the standardized test statistic?
f. What is the statistical decision in statement form?
Step by step
Solved in 5 steps with 3 images
