STATS 3 QUESTIONS WITH
ACCURATE ANSWERS
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. If
α = .05, what is the critical t value? correct answer ±2.447
H0: µ = 6.6; H1: µ ≠ 6.6. The t critical values for a two-tailed test at the 0.05
significance level with n − 1, or 6 degrees of freedom are ±2.447.
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
What is the sample mean? correct answer 7.6
The sample mean is 7.557, rounded to 7.6. It is found by summing all the values
(52.9) and dividing by the sample size (7).
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
What is the sample standard deviation? correct answer 1.177
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
What is variance of this sample? correct answer 1.386
, A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
When evaluated using the 5% level of significance, which of the following would
be the best decision/interpretation of the null hypothesis? correct answer Fail to
reject the null hypothesis.
A large department store examined a sample of the 18 credit card sales and
recorded the amounts charged for each of three types of credit cards:
MasterCard, Visa, and Discover. Six MasterCard sales, seven Visa, and five
Discover sales were recorded. The store used an ANOVA to test if the mean sales
for each credit card were equal. What are the degrees of freedom for the F
statistic? correct answer 2 in the numerator, 15 in the denominator
A manufacturer wants to increase the shelf life of a line of cake mixes. Past
records indicate that the average shelf life of the mix is 216 days. After a revised
mix has been developed, a sample of nine boxes of cake mix gave these shelf lives
(in days): 215, 217, 218, 219, 216, 217, 217, 218, and 218. Using α = 0.025, has the
shelf life of the cake mix increased? correct answer Yes, because computed t is
greater than the critical value.
A p-value is the same as a stated significance level. correct answer False
A test statistic is a value, determined from sample information, used to decide
whether to reject the null hypothesis. correct answer True
An example of a NULL hypothesis is: A person is innocent until proven guilty.
correct answer True
ACCURATE ANSWERS
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. If
α = .05, what is the critical t value? correct answer ±2.447
H0: µ = 6.6; H1: µ ≠ 6.6. The t critical values for a two-tailed test at the 0.05
significance level with n − 1, or 6 degrees of freedom are ±2.447.
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
What is the sample mean? correct answer 7.6
The sample mean is 7.557, rounded to 7.6. It is found by summing all the values
(52.9) and dividing by the sample size (7).
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
What is the sample standard deviation? correct answer 1.177
A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
What is variance of this sample? correct answer 1.386
, A hypothesis regarding the weight of newborn infants at a community hospital is
that the mean is 6.6 pounds. A sample of seven infants is randomly selected and
their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.
When evaluated using the 5% level of significance, which of the following would
be the best decision/interpretation of the null hypothesis? correct answer Fail to
reject the null hypothesis.
A large department store examined a sample of the 18 credit card sales and
recorded the amounts charged for each of three types of credit cards:
MasterCard, Visa, and Discover. Six MasterCard sales, seven Visa, and five
Discover sales were recorded. The store used an ANOVA to test if the mean sales
for each credit card were equal. What are the degrees of freedom for the F
statistic? correct answer 2 in the numerator, 15 in the denominator
A manufacturer wants to increase the shelf life of a line of cake mixes. Past
records indicate that the average shelf life of the mix is 216 days. After a revised
mix has been developed, a sample of nine boxes of cake mix gave these shelf lives
(in days): 215, 217, 218, 219, 216, 217, 217, 218, and 218. Using α = 0.025, has the
shelf life of the cake mix increased? correct answer Yes, because computed t is
greater than the critical value.
A p-value is the same as a stated significance level. correct answer False
A test statistic is a value, determined from sample information, used to decide
whether to reject the null hypothesis. correct answer True
An example of a NULL hypothesis is: A person is innocent until proven guilty.
correct answer True
