An engineer who is studying the tensile strength of a steel alloy intended for use in golf club shafts knows that tensile strength is approximately normally distributed with σ=75 psi. a random sample of 12 specimens has a sample mean tensile strength of 3450 psi. is there evidence to support the claim that mean strength is greater than 3400 psi. state and test the hypothesis at significance level α =0.01. (2 points)

We conclude that the mean strength is equal to 3400 psi.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 3400 psi

Sample mean, = 3450 psi

Sample size, n = 12

Alpha, α = 0.051

Population standard deviation, σ =75 psi

First, we design the null and the alternate hypothesis

We use one-tailed(right) z test to perform this hypothesis.

Formula:

Putting all the values, we have

Now,

Since,  

We fail to reject the null hypothesis and accept the null hypothesis. Thus, we conclude that the mean strength is equal to 3400 psi.

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.

5

step-by-step explanation: