The factory building manager at Delectable Delights, Jason Short, is concerned that the new contractor he hired is taking too long to replace defective lights in the factory workspace. He would like to perform a hypothesis test to determine if the replacement time for the lights under the new contractor is in fact longer than the replacement time under the previous contractor, which was 3.2 days on average. He selects a random sample of 12 service calls to replace defective lights and obtains the following times to replacement (in days). Use a significance level of 0.05. 6.2 7.1 5.4 5.5 7.5 2.6 4.3 2.9 3.7 0.7 5.6 1.7
1. Define μ in the context of the problem and state the appropriate hypotheses. (5 pts)
2. Regardless of your results in Part B, calculate the appropriate test statistic by hand. Write out all your steps.
3. What is your decision regarding the null hypothesis? (In other words, do you reject or fail to reject and why?)
4. Write a final concluding statement to Jason giving the results of the hypothesis test. (In other words, write the final summary statement.)

H0 : μ = 3.2

H1 : μ > 3.2

1.982

We fail to reject the Null ;

There is no significant evidence to conclude that the mean replacement time under the new contractor takes longer than the usual average time.

Step-by-step explanation:

μ = average time taken by the previous contractor. ; μ = 3.2

H0 : μ = 3.2

H1 : μ > 3.2

Sample size, n = 12 ;

X = 6.2 7.1 5.4 5.5 7.5 2.6 4.3 2.9 3.7 0.7 5.6 1.7

xbar = Σx / n = 53.2 / 12 = 4.43

Standard deviation, s ; using a calculator :

s = 2.15

B.)

The test statistic :

(xbar - μ) ÷ (s / sqrt(n))

(4.43 - 3.2) ÷ (2.15 / sqrt(12))

1.23 ÷ 0.62065

= 1.982

C.)

Decision Region :

If Pvalue < α ; Reject the null

α = 0.05

Pvalue :

P(x < 1.982) = 0.9762

0.9762 > 0.05 ; Hence, we fail to reject the Null

There is no significant evidence to conclude that the mean replacement time under the new contractor takes longer than the usual average time.

8(-10x+3.5y-7)

8×-10x + 8×3.5y + 8×-7

-80x + 28y - 56

therefore

-80x+28y-56 is the correct answer

d

step-by-step explanation:

hello and welcome!

so, when we see the words "proportional" along with a table, we need to know that we're looking numbers that divide by the same thing.

looking at this table, we simply have to do a trial and error, and divide to see which numbers have the same quotient. if you look at choice a & c, they both have equal quotients for three of the numbers, with one exception, so those can't be the answer. looking at b, there is no similarity, so that can't be it. then, we see d; if you divide all the numbers in the table, you'll see that they all divide by two, which is a proportional relationship, and our answer!

also, always remember that the x will always be the number that goes into y, and somewhere behind this table, is a formula. for this specific table, the formula would be:

since our x-value is being divided by two to get the y-value. and if they were to ask for more numbers in the series, this is the formula you would use to find them.