Chegg A manufacturer of submersible pumps claims that at most 30% of the pumps require repairs within the first 5 years of operations. A random sample of 120 of these pumps included 47 which required repairs within the first 5 years. Does the manufacturer’s claim appear to be true, at the 0.05 level of significance?

No, the manufacturer’s claim doesn't appear to be true, at the 0.05 level of significance.

Step-by-step explanation:

We are given that a manufacturer of submersible pumps claims that at most 30% of the pumps require repairs within the first 5 years of operations. A random sample of 120 of these pumps included 47 which required repairs within the first 5 years.

We have to test the manufacturer’s claim.

Firstly, as we know that the testing is done always on the population parameter.

Let p = % of the pumps that require repairs within the first 5 years of operations.

SO, Null Hypothesis, : 30%  {means that at most 30% of the pumps require repairs within the first 5 years of operations}

Alternate Hypothesis, : p > 30%   {means that more than 30% of the pumps require repairs within the first 5 years of operations}

The test statistics that will be used here is One-sample z proportion test;

                    T.S. =  ~ N(0,1)

where, = proportion of the pumps that require repairs within the first 5 years of operations in a sample of 120 =

            n = sample of pumps  120

So, test statistics  =

                               = 2.057

Now, at 0.05 level of significance, the z table gives critical value of 1.6449. Since our test statistics is more than the critical value of z so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region.

Therefore, we conclude that more than 30% of the pumps require repairs within the first 5 years of operations which means the manufacturer’s claim was not true.

19.side- angle- side

20. angle- side- angle

step-by-step explanation:

let's solve your equation step-by-step.

24−3x=−27

step 1: simplify both sides of the equation.

24−3x=−27

24+−3x=−27

−3x+24=−27

step 2: subtract 24 from both sides.

−3x+24−24=−27−24

−3x=−51

step 3: divide both sides by -3.

−3x

−3

=

−51

−3

x=17

answer:

x=17

step-by-step explanation:

mark brainliest and have a great day!