MGSC291 Test 2

True or False: Given a right tailed hypothesis test, if the value of this test statistic is 1.82 and the critical value is 1.645, then we fail to reject the null hypothesis.

False

we do not reject the null hypothesis when the p-value is

_> a

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

confidence interval for the population proportion

each t distribution is identified by its

degrees of freedom

whenever we construct a confidence interval for the population mean, the margin of error includes the standard error of x(bar) and the

desired level of confidence

when estimating a population mean, the t(df) distribution is used when the

population variance is unknown

The mean and standard deviation are often used to describe ____ data, while the proportion is a descriptive measure that can also be used for ____ data.

quantitative, qualitative

when the population standard deviation is unknown the standard error for the sample mean is calculated as

s / √n

the critical value of a hypothesis test is

separates the rejection region from the non-rejection region

Which of the following is necessary for creating confidence intervals for the population mean?

Normality of the estimator

suppose you are constructing a confidence interval for the population mean. For a given sample size and population standard deviation, how will the width of the interval change as the confidence level increases?

it gets larger

in order to derive a confidence interval for m, the estimator x(bar) must have a

normal sampling distribution

A two tailed test of the population mean is conducted at a=.10. The calculated test statistic is z=1.55 and P(z>1.55)=0.0606. The null hypothesis should ____.

not be rejected bc the p-value = 0.1212 > 0.10

which of the following is a descriptive measure for a qualitative variable? Proportion Median Standard Deviation Mean

Proportion

True or False: A confidence interval provides a range of values that should contain a population parameter with a certain level of confidence

True

A 95% confidence interval for the population mean implies that

for repeated samples, 95% of the sample means with fall within the interval

the most practical way to reduce the margin of error is

increase the sample size

Suppose you and constructing a confidence interval for the population mean. for a given confidence level and sample size, the width of the interval is wider for

larger standard deviation

when constructing a confidence interval for the population mean, the factors that affect the width of the confidence interval for a given standard deviation are

the confidence level and the sample size

Suppose you and constructing a confidence interval for the population mean. For a given sample size and standard deviation, the width of the confidence interval is ____ for a greater confidence level

wider