E370 Exam 3 Conceptual
Which of the following types of tests about the population parameter may be performed?
upper tail, lower tail, and two tail tests
For the confidence interval of the mean when the population standard deviation is known and the sample is large, the proper distribution to use is
the standard normal distribution
A point estimator refers to an estimator that provides a single value. T/F?
true
On the basis of sample information, we can either "accept the null hypothesis" or "reject the null hypothesis". T/F?
False -we either reject the null hypothesis or do not reject the null hypothesis
A university is interested in promoting graduates of tis honors program by establishing that the mena GPA of these graduates exceeds 3.50. A sampleof 36 hours students is taken and is found to have a mean GPA equal to 3.60. To establish whether the mena GPA exceeds 3.50, the appropriate hypotheses are
H0: mu <= 3.50 H1: mu > 3.50
What represents an appropriate NULL hypothesis in the lower tail test
H0: mu >=0
Which of the following represents an appropriate set of hypotheses
H0: mu=0 H1: mu does not = 0
In a one tail test, the rejection region is located under one tail (upper or lower) of the corresponding sampling distribution, while in a two tail test this region is located under both tails. T/F?
True
In the hypothesis test, the null hypothesis is believed to be true unless there is overwhelming evidence to the contrary. T/F?
True
The alternative hypothesis typically
contests the status quo
As sample size n increases, the confidence interval becomes
narrower
As the confidence level decreases, the confidence interval becomes
narrower
What is an example of something that represents an estimate
p-bar= 0.8
What is the most typical form of a calculated confidence interval
point estimate +/- margin of error
What is an example of something that represents an estimator
s^2
the hypothesis H0: mu=/0 is an example of
the alternative hypothesis in a two tail test
when conducting a hypothesis test for the population mean when the population standard deviation is known, the critical value and the p value are computed using
the standard normal deviation
When s is used to estimate the confidence interval for the mean, the margin of error is computed by using
the t-distribution
When a statistic is used to estimate a parameter, the statistic is referred to as an estimator. A particular value of the estimator is called an estimate. T/F?
true
What type of error occurs if you fail to reject H0 when, in fact, it is not true?
type II
A university is interested in promoting graduates of its honors program by establishing that the mean GPA of these graduates exceeds 3.50. A sample of 36 honors students is taken and is found to have a mean GPA equal to 3.60. The population standard deviation is assumed to equal 0.40. Suppose that you calculated that the p-value for the test with the given information equal to 0.067. At a 10% significance level, the decision is to
we reject H0, because the p-value is below the significance level, alpha= 0.1
The confidence intervals for the population proportion are generally based on
z distribution
A university is interested in promoting graduates of its honors program by establishing that the mean GPA of these graduates exceedds 3.50. A sample of 36 honors students is taken and is found to have a mean GPA equal to 3.60. The population standard deviation is assumed to equal 0.40. The value of the test statistic is
zx-bar= 1.50
Excel function to find p-value
1-NORM.S.DIST(1.5,TRUE)