Question

1.

A) A manufacturer of sprinkler systems designed for fire protection claims that the average activating temperature is at least 135 degrees F. To test this claim, you randomly select a sample of 32 systems and find the mean activation temperature to be 133 degrees F. Assume the population standard deviation is 3.3 degrees F. At a=0.10, do you have enough evidence to reject the null hypothesis? 10 points.       Ho: u>= 135 Ha: u<135.

B) In auto racing, a pit stop is where a racing vehicle stops for new tires fuel, repairs, and other such adjustments. The efficiency of a pit crew can affect the outcome of a race. A pit crew claims that its mean put stop time is less than 13 seconds. A random sample of 32 pit stop times has a sample mean of 12.9 seconds. The population standard deviation is 0.19 seconds. Is there enough evidence to support the claim at a=0.01?       Ho: u>=13 seconds Ha: u< 13 seconds.

Answer 1

Here we can use ti-83 calculator.

A)

Test Hypothesis :

H0: u ≥ 135

Ha: u < 135

Test statistic :

Z = -3.43

P-value :

p = 0.0003

Conclusion : p-value is less than alpha=0.10 then conclude that reject the null hypothesis (H0).

B)

Test Hypothesis :

H0: u ≥ 13

Ha: u < 13

Test statistic :

Z = - 2.98

P-value:

p=0.0015

Conclusion :

P-value is less than alpha=0.01 then conclude that reject the null hypothesis H0.