An engineer measured the brinell hardness of 25 pieces of ductile iron that were subcritically annealed. the sample average was found to be =172.52. the engineer needs to test if the mean brinell hardness of all such ductile iron pieces is greater than 170. assume that brinell hardness is normally distributed with standard deviation of ? ? =10.

a. write down the null and alternative hypotheses to be tested.

b. test the hypotheses at ? ? =0.05, using the test statistic approach. what is your decision on null )? interpret the test results.

c. construct a 95% confidence interval for the mean brinell hardness. test the hypotheses using the confidence interval method. do you get the same answer as in part (b)?

d. what is the ? ? for the test? test the hypotheses using the ? ? do you get the same answer as parts (b) and (c)?

(x3 + 6x2 + 2x - 6) • (x - 1)

step-by-step explanation:

polynomial long division :

3.2     polynomial long division

dividing :   x4+5x3-4x2-8x+6

                              ("dividend")

by         :     x-1     ("divisor")

dividend     x4   +   5x3   -   4x2   -   8x   +   6

- divisor   * x3     x4   -   x3            

remainder         6x3   -   4x2   -   8x   +   6

- divisor   * 6x2         6x3   -   6x2        

remainder             2x2   -   8x   +   6

- divisor   * 2x1             2x2   -   2x    

remainder               -   6x   +   6

- divisor   * -6x0               -   6x   +   6

remainder                     0

quotient :   x3+6x2+2x-6   remainder:   0

part a

in a city ice cream is mostly only bought when the temperature is very high as ice cream cools down our

so we can derive the conclusion that as the temperature increases the number of ice creams sold also increases

part b

y intercept is 5

slope is 2

happy to

pls mark as brainliest

b.my answer is b.

brainliest

whats the question?

step-by-step explanation: