CCLE FINAL QUIZES QUESTIONS AND ANSWERS
When stating the null and alternative hypotheses, the hypotheses are:
Select one:
a. Always about the parameter only
b. Always about the statistic only
c. Always about both the statistic and the parameter
d. Sometimes about the statistic and sometimes about the parameter - Answer -a.
Always about the parameter only
The probability of rejecting the null hypothesis when, in fact, the null hypothesis is true
is called the
Select one:
a. significance level
b. power of the test
c. standard error
d. p-value - Answer -a. significance level
A janitor at a large office building believes that his supply of light bulbs has a defect rate
that is higher than the defect rate stated by the manufacturer. The janitor's null
hypothesis is that the supply of light bulbs has a manufacturer's defect rate of p = 0.09.
He performs a test at a significance level of 0.01. The null and alternative hypothesis
are as follows: H0 : p = 0.09 and Ha : p > 0.09.
Choose the statement that best describes the significance level in the context of the
hypothesis test.
Select one:
a. The significance level of 0.01 is the probability of concluding the defect rate is more
than 0.09 when it is equal to 0.09.
b. The significance level of 0.01 is the z-statistic that we will use to compare the
observed outcome to the null hypothesis.
c. The significance level of 0.01 is the probability of concluding that the defect rate is
equal to 0.09 when in fact it is greater than 0.09.
d. The sig - Answer -a. The significance level of 0.01 is the probability of concluding the
defect rate is more than 0.09 when it is equal to 0.09.
Suppose that a one-proportion z-test statistic for a study is calculated to be 2.45. Which
of the following is the most appropriate interpretation of this statistic?
Select one:
a. The study results are statistically significant.
, b. The observed value of the sample proportion is 2.45 SDs away from the parameter
value assumed by the null hypothesis.
c. The observed value of the sample proportion is 2.45 times the parameter value
assumed by the null hypothesis.
d. The observed value of the sample proportion is 2.45 SDs above the parameter value
assumed by the null hypothesis. - Answer -d. The observed value of the sample
proportion is 2.45 SDs above the parameter value assumed by the null hypothesis.
A quality control manager thinks that there is a higher defective rate on the production
line than the advertised value of p = 0.025. She does a hypothesis test with a
significance level of 0.05. Symbolically, the null and alternative hypothesis are as
follows: H0: p = 0.025 and Ha: p > 0.025. She calculates a p-value for the hypothesis
test of defective light bulbs to be approximately 0.067.
Choose the correct interpretation for the p-value.
Select one:
a. The p-value tells us that the result is significantly higher than the advertised value
using a significance level of 0.05.
b. The p-value tells us that the probability of concluding that the defect rate is equal to
0.025, when in fact it is greater than 0.025, is approximately 0.067.
c. The p-value tells us that the true population rate of defective light bulbs is
approximately 0.067.
d. The p-value tells us that if the defect rate is 0.025, then the probability - Answer -d.
The p-value tells us that if the defect rate is 0.025, then the probability that she would
observe the percentage she actually observed or higher is 0.067. At a significance level
of 0.05, this would not be an unusual outcome.
A researcher conducts a hypothesis test on a population proportion. Her null and
alternative hypothesis are H0 : p = 0.4 and Ha : p < 0.4 . The test statistic and p-value
for the test are z = −3.01 and p−value = 0.0013 .
For a significance level of α = 0.05 , choose the correct conclusion regarding the null
hypothesis.
Select one:
a. There is not sufficient evidence to reject the null hypothesis that the population
proportion is equal to 0.4.
b. There is not sufficient evidence to conclude that the population proportion is
significantly less than 0.4.
c. There is sufficient evidence to accept the null hypothesis that the population
proportion is equal to 0.4.
d. There is sufficient evidence to conclude that the population proportion is significantly
less than 0.4. - Answer -d. There is sufficient evidence to conclude that the population
proportion is significantly less than 0.4.
When stating the null and alternative hypotheses, the hypotheses are:
Select one:
a. Always about the parameter only
b. Always about the statistic only
c. Always about both the statistic and the parameter
d. Sometimes about the statistic and sometimes about the parameter - Answer -a.
Always about the parameter only
The probability of rejecting the null hypothesis when, in fact, the null hypothesis is true
is called the
Select one:
a. significance level
b. power of the test
c. standard error
d. p-value - Answer -a. significance level
A janitor at a large office building believes that his supply of light bulbs has a defect rate
that is higher than the defect rate stated by the manufacturer. The janitor's null
hypothesis is that the supply of light bulbs has a manufacturer's defect rate of p = 0.09.
He performs a test at a significance level of 0.01. The null and alternative hypothesis
are as follows: H0 : p = 0.09 and Ha : p > 0.09.
Choose the statement that best describes the significance level in the context of the
hypothesis test.
Select one:
a. The significance level of 0.01 is the probability of concluding the defect rate is more
than 0.09 when it is equal to 0.09.
b. The significance level of 0.01 is the z-statistic that we will use to compare the
observed outcome to the null hypothesis.
c. The significance level of 0.01 is the probability of concluding that the defect rate is
equal to 0.09 when in fact it is greater than 0.09.
d. The sig - Answer -a. The significance level of 0.01 is the probability of concluding the
defect rate is more than 0.09 when it is equal to 0.09.
Suppose that a one-proportion z-test statistic for a study is calculated to be 2.45. Which
of the following is the most appropriate interpretation of this statistic?
Select one:
a. The study results are statistically significant.
, b. The observed value of the sample proportion is 2.45 SDs away from the parameter
value assumed by the null hypothesis.
c. The observed value of the sample proportion is 2.45 times the parameter value
assumed by the null hypothesis.
d. The observed value of the sample proportion is 2.45 SDs above the parameter value
assumed by the null hypothesis. - Answer -d. The observed value of the sample
proportion is 2.45 SDs above the parameter value assumed by the null hypothesis.
A quality control manager thinks that there is a higher defective rate on the production
line than the advertised value of p = 0.025. She does a hypothesis test with a
significance level of 0.05. Symbolically, the null and alternative hypothesis are as
follows: H0: p = 0.025 and Ha: p > 0.025. She calculates a p-value for the hypothesis
test of defective light bulbs to be approximately 0.067.
Choose the correct interpretation for the p-value.
Select one:
a. The p-value tells us that the result is significantly higher than the advertised value
using a significance level of 0.05.
b. The p-value tells us that the probability of concluding that the defect rate is equal to
0.025, when in fact it is greater than 0.025, is approximately 0.067.
c. The p-value tells us that the true population rate of defective light bulbs is
approximately 0.067.
d. The p-value tells us that if the defect rate is 0.025, then the probability - Answer -d.
The p-value tells us that if the defect rate is 0.025, then the probability that she would
observe the percentage she actually observed or higher is 0.067. At a significance level
of 0.05, this would not be an unusual outcome.
A researcher conducts a hypothesis test on a population proportion. Her null and
alternative hypothesis are H0 : p = 0.4 and Ha : p < 0.4 . The test statistic and p-value
for the test are z = −3.01 and p−value = 0.0013 .
For a significance level of α = 0.05 , choose the correct conclusion regarding the null
hypothesis.
Select one:
a. There is not sufficient evidence to reject the null hypothesis that the population
proportion is equal to 0.4.
b. There is not sufficient evidence to conclude that the population proportion is
significantly less than 0.4.
c. There is sufficient evidence to accept the null hypothesis that the population
proportion is equal to 0.4.
d. There is sufficient evidence to conclude that the population proportion is significantly
less than 0.4. - Answer -d. There is sufficient evidence to conclude that the population
proportion is significantly less than 0.4.
