An engineer designed a valve that will regulate water pressure on an automobile engine. the engineer designed the valve such that it would produce a mean pressure of 4.1 pounds/square inch. it is believed that the valve performs above the specifications. the valve was tested on 120 engines and the mean pressure was 4.3 pounds/square inch. assume the variance is known to be 0.64. a level of significance of 0.05 will be used. make a decision to reject or fail to reject the null hypothesis. make a decision.

We reject the null hypothesis at the significance level of 0.05.

Step-by-step explanation:

vs (upper-tail alternative)

We have , and n = 120. We have a large sample and our test statistic is

which is normal standard approximately. We have observed

.

We should use the significance level . The 95th quantile of the standard normal distribution is and the rejection region is given by {z > 1.6449}. Because the observed value 2.7386 is greater than 1.6449, we reject the null hypothesis at the significance level of 0.05.

the answer is d

step-by-step explanation:

y+3=-4(x-2)

y+3=-4x+8

  -3         -3  

y=-4x+5

x=half

step-by-step explanation: