Dullco manufacturing claims that its alkaline batteries last at least 40 hours on average in a certain type of portable cd player. but tests on a random sample of 18 batteries from a day's large production run showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours. in a left-tailed test at α = .05, which is the most accurate statement?

we would strongly reject the claim.

we would clearly fail to reject the claim.

we would face a rather close decision.

we would switch to α = .01 for a more powerful test.

We would face a rather close decision and switch to α = .01 for a more powerful test.

Step-by-step explanation:

We are given the following in the question:  

Population mean, μ = 40 hours

Sample mean, = 37.8 hours

Sample size, n = 108

Alpha, α = 0.05

Sample standard deviation, s = 5.4 hours

First, we design the null and the alternate hypothesis

We use one-tailed t 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 alkaline batteries last at least 40 hours on average in a certain type of portable CD player.

But we faced a close decision. By decreasing alpha we could get stronger results. We would switch to α = .01 for a more powerful test.

d

step-by-step explanation:

in a an geometric explicit equation, the first number is the starting rate. in this case 10.

the circle graph is not a function.

step-by-step explanation:

the graph of the circle is not a function.

because for a graph to be a function, each value of x must give one value of y

in the circle, the values of x for -2< x< 2 each give 2 values of y.

hence this is not a function.