Question

Car inspectors inspect new models of cars to see if they are safe for human passengers. This can be thought of as a hypothesis test with the following hypotheses.

• H₀: the car is safe
• H_a: the car is not safe

The following is an example of what type of error?

The sample suggests that the new model of car is safe, but it actually is not safe.

a. type I

b. type II

c. not an error

Question 2 of 6

Car inspectors inspect new models of cars to see if they are safe for human passengers. This can be thought of as a hypothesis test with the following hypotheses.

• H₀: the car is safe
• H_a: the car is not safe

The following is an example of what type of error?

The sample suggests that the new model of car is not safe, but it actually is safe.

a. type I

b. type II

c. not an error

Question 3 of 6

A manufacturer of a portable cell phone charger markets its batteries as having, on average, 3.5 hours to rapidly charge to full capacity. A consumer group decides to test this claim by assessing the length of time that 30 of their chargers take to be fully charged and finds the average is 3.7 hours, with a standard deviation of .25.

The resulting p-value is .02852; thus, the null hypothesis is rejected. The consumer group concludes that the manufacturer’s claim that its portable cellphone charger can be recharged, on average, 3.5 hours is inaccurate.

What type of error is possible in this situation?

a. type I

b. type II

c. not an error

d. both

Question 4 of 6

A manufacturer of a portable cell phone charger markets its batteries as having, on average, 3.5 hours to rapidly charge to full capacity. A consumer group decides to re-test this claim by assessing the length of time that 30 of their chargers take to be fully charged and finds the average is 3.6 hours, with a standard deviation of .45.

The resulting p-value is .41222; thus, the null hypothesis is not rejected. The consumer group concludes that the manufacturer’s claim that its portable cellphone charger can be recharged, on average, 3.5 hours is accurate.

What type of error is possible in this situation?

a. type I

b. type II

c. not an error

d. both

Question 5 of 6

Suppose the results indicate that the null hypothesis should be rejected; thus, it is possible that a type I error has been committed.

Given the type of error made in this situation, what could researchers do to reduce the risk of this error?

a.Increase the sample size

b.Use a z-test

c. Use a t-test

d.Only use the data given a normal distribution

e.None of the above

Question 6 of 6

Suppose the results indicate that the null hypothesis should not be rejected; thus, it is possible that a type II error has been committed.Given the type of error made in this situation, what could researchers do to reduce the risk of this error?

a.Increase the sample size

b.Decrease the sample size

c. Increase the significance level

d.Decrease the significance level.

Answer 1

1) we accept null hypothesis but it actually not correct

Hence we make Type 1 error

2)we reject null hypothesis but is actually true

Hence we makt

Type 2 error

3)here sample evidence reject the manufacturer claim but actually it may be correct.

Hence possible error is

Type 1 error

4)here sample evidence support the manufacturers claim,

That is possible error in the test is

Type 2 error

5)to reduce the risk of committed error we have to

Increase the sample size.

6)to reduce the risk of type 2 error one should

Increase the sample size.