250 - 150 = 100
100 / 250 = .40
.40 converted into a percent is 40%
40%
So I am not 100% certain. But I think it is A.
Answer:
So the value of the test statistic is -0.85.
Step-by-step explanation:
We know that a sample of 1800 computer chips revealed that 53% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature states that 54% of the chips do not fail in the first 1000 hours of their use.
We get that:
We calculate the standar deviation:
We calculate the value of the test statistic:
So the value of the test statistic is -0.85.