Quiz Definitions

A fast-food franchise is considering building a restaurant at a busy intersection. A financial advisor determines that the site is acceptable only if, on average, more than 300 automobiles pass the location per hour. The advisor tests the following hypotheses: Ho: μ ≤ 300. HA: μ > 300. The consequences of committing a Type II error would be that

the franchiser does not build on an acceptable site

A local courier service advertises that its average delivery time is less than 6 hours for local deliveries. When testing the two hypotheses, Ho:μ ≥ 6 and HA:μ < 6, μ stand for

the mean delivery time

3.If the null hypothesis is rejected at a 1% significance level, then

the null hypothesis will be rejected at a 5% significance level

10. For a given confidence level and sample size n, the width of the confidence interval for the population mean is narrower, the greater the population standard deviation σ.

FALSE

8. For a given sample size n and population standard deviation σ, the width of the confidence interval for the population mean is wider, the smaller the confidence level

FALSE

A Type II error is made when we reject the null hypothesis and the null hypothesis is actually false.

False

What is the decision rule when using the p-value approach to hypothesis testing?

Reject Ho if the p-value < α.

4.It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock. A politician claims that the proportion of babies born out of wedlock is increasing. In testing the politician?s claim, how does one define the population parameter of interest?

The current proportion of babies born out of wedlock

A hypothesis test regarding the population mean µ is based on the sampling distribution of the sample me

True

1.A Type I error occurs when we

reject the null hypothesis when it is actually true

In general, the null and alternative hypotheses are __________.

Mutually Exclusive

The hypothesis statement H: µ = 25 is an example of a(an) ________ hypothesis.

NULL

For a given confidence level and population standard deviation σ, the width of the confidence interval for the population mean is wider, the smaller the sample size n.

True

Under the assumption that the null hypothesis is true as an equality, the p-value is the likelihood of observing a sample mean that is at least as extreme as the one derived from the given sample.

True

Consider the following hypotheses that relate to the medical field: Ho: A person is free of disease. HA: A person has disease. In this instance, a Type II error is often referred to as ___

a false negative

Consider the following hypotheses that relate to the medical field: Ho: A person is free of disease. HA: A person has disease. In this instance, a Type I error is often referred to as ___

a false positive

3. Statisticians like precision in their interval estimates. A low margin of error is needed to achieve this. Which of the following supports this when selecting sample sizes?

a. A larger sample size reduces the margin of error. i.If we are able to increase the size of the sample, the larger nreduces the margin of error for the interval estimates.

11.For a given sample size and population standard deviation, which of the following is true in the interval estimation of the population mean?

a. If the confidence level is greater, the interval is wider. i. For a given sample size and population standard deviation, the greater the confidence level, the wider the confidence interval.

22. For a given confidence level and population standard deviation, which of the following is true in the interval estimation of the population mean?

a. If the sample size is bigger, the interval is narrower. i. For a given confidence level and population standard deviation, the bigger the sample size n, the narrower the confidence interval.

23.When the required sample size calculated by using a formula is not a whole number, what is the best choice for the required sample size?

a. Round the result of the calculation up to the nearest whole number. i. To be conservative, always round up noninteger values of the calculated required sample size.

6.Consider the following competing hypotheses: Ho:μ = 0, HA:μ ≠ 0. The value of the test statistic is z = −1.38. If we choose a 5% significance level, then we

do not reject the null hypothesis and conclude that the population mean is not significantly different from zero

A Type II error occurs when we ___________.

do not reject the null hypothesis when it is actually false

If the p-value for a hypothesis test is 0.07 and the chosen level of significance is α = 0.05, then the correct conclusion is to ____________________.

not reject the null hypothesis

2. The sampling distribution of the population proportion is based on a binomial distribution. What condition must be met to use the normal approximation for the confidence interval?

np> 5 and n(1-p)>5 check notes for real answer

5.For a given sample size n

decreasing the probability of a Type I error α will increase the probability of a Type II error β

13.If calculated required sample size is a noninteger value, we should always _______ calculated value.

Round up

12. An analyst takes a random sample of 25 firms in the telecommunications industry and constructs a confidence interval for the mean return for the prior year. Holding all else constant, if he increased the sample size to 30 firms, how are the standard error of the mean and the width of the confidence interval affected

Standard Error of the mean Decreases Width of confidence interval becomes narrower

7. The main ingredient for developing a confidence interval is the sampling distribution of the underlying statistic.

TRUE b. The main ingredient for developing a confidence interval is the sampling distribution of the underlying statistic.

1. If a random sample of size n is taken from a normal population with a finite variance, then the statistic follows the tdf distribution with (n −1) degrees of freedom, df.

True

2.A Type I error is committed when we reject the null hypothesis, which is actually true.

True

7.For a given sample size, any attempt to reduce the likelihood of making one type of error (Type I or Type II) will increase the likelihood of the other error.

True

8.In a one-tailed test, the rejection region is located under one tail (left or right) of the corresponding probability distribution, while in a two-tailed test this region is located under both tails.

True

19.When examining the possible outcome of an election, what type of confidence interval is most suitable for estimating the current support for a candidate?

a. The confidence interval for the population proportion i. Sometimes the parameter of interest describes a population that is qualitative rather than quantitative. The population proportion is the essential descriptive measure of when the data type is qualitative.

9The hypothesis statement H: μ < 60 is an example of a(an) ________ hypothesis.

alternative

If the p-value for a hypothesis test is 0.027 and the chosen level of significance is α = 0.05, then the correct conclusion is to ________________.

reject the null hypothesis

A fast-food franchise is considering building a restaurant at a busy intersection. A financial advisor determines that the site is acceptable only if, on average, more than 300 automobiles pass the location per hour. The advisor tests the following hypotheses: Ho: μ ≤ 300. HA: μ > 300. The consequences of committing a Type I error would be that__

the franchiser builds on an unacceptable site