Construct a 95 confidence interval for the population mean, . Assume the population has a normal distribution. A random sample of 16 lithium batteries has a mean life of 645 hours with a standard deviation of 31 hours.
Round to the nearest tenth. A) (628.5, 661.5 ) B) (876.2, 981.5 ) C) (531.2, 612.9 ) D) (321.7, 365.8)
Q. 2Suppose a brewery has a filling machine that fills 12 ounce bottles of beer. It is known that the amount of beer poured by this filling machine follows a normal distribution with a mean of 12.10 ounces and a standard deviation of 0.04 ounce.
Find the probability that the bottle contains between 12.00 and 12.06 ounces. A) 0.1525 B) 0.8351 C) 0.1649 D) 0.8475
Q. 3Suppose a brewery has a filling machine that fills 12 ounce bottles of beer. It is known that the amount of beer poured by this filling machine follows a normal distribution with a mean of 12.14 onces and a standard deviation of 0.04 ounce.
Find the probability that the bottle contains more than 12.14 ounces of beer. A) 0.5 B) 1 C) 0 D) 0.4
Q. 4Construct a 95 confidence interval for the population mean, . Assume the population has a normal distribution. A sample of 25 randomly English majors has a mean test score of 81.5 with a standard deviation of 10.2.
Round to the nearest hundredth. A) (77.29, 85.71 ) B) (56.12, 78.34 ) C) (66.35, 69.89 ) D) (87.12, 98.32 )
Q. 5Suppose a brewery has a filling machine that fills 12 ounce bottles of beer. It is known that the amount of beer poured by this filling machine follows a normal distribution with a mean of 12.18 ounces and a standard deviation of 0.04 ounce.
Find the probability that the bottle contains fewer than 12.08 ounces of beer. A) 0.0062 B) 0.4938 C) 0.9938 D) 0.5062
Q. 6Wanting to enjoy the beautiful weather, Cassie took a walk with no destination in mind. At each four-way intersection, she randomly decided to head either south or west.
A summary of her walk is shown below.
S S S S S W W S W S
S S S S S S W W W S
S W W S W S W S W S
W W W S S W W W S W
Is there evidence at the a = 0.05 level of significance to support the hypothesis that Cassie's walk was not
random?
A) z = -0.26
Since z < z0.025 = 1.96, we do not reject H0. There is not sufficient evidence to support the hypothesis
that her walk was not random.
B) z = -0.91
Since z < z0.025 = 1.96, we do not reject H0. There is not sufficient evidence to support the hypothesis
that her walk was not random.
C) z = -5.43
Since z > z0.025 = 1.96, we reject H0. There is sufficient evidence to support the hypothesis that her
walk was not random.
D) z = -3.50
Since z > z0.025 = 1.96, we reject H0. There is sufficient evidence to support the hypothesis that her
walk was not random.
Q. 7The two flavors of ice cream in a taste test are supposed to be administered to respondents in a random fashion.
Suspecting that the administrators of the test did not follow the randomness rule, the project statistician examines the flavor order for the day's taste testing, shown below. vanilla chocolate vanilla chocolate chocolate chocolate vanilla chocolate vanilla vanilla chocolate vanilla chocolate vanilla chocolate vanilla chocolate vanilla chocolate vanilla Is there evidence at the a = 0.05 level of significance to support the hypothesis that the flavor order is not random? A) r = 17; lower critical value = 6; upper critical value = 16
Since r = 16, we reject H0. There is sufficient evidence to support the hypothesis that the sequence is not
random.
B) r = 16; lower critical value = 7; upper critical value = 18
Since 7 < r < 18, we do not reject H0. There is not sufficient evidence to support the hypothesis that the
sequence is not random.
C) r = 18; lower critical value = 7; upper critical value = 18
Since r = 18, we reject H0. There is sufficient evidence to support the hypothesis that the sequence is not
random.
D) r = 15; lower critical value = 6; upper critical value = 16
Since 7 < r < 18, we do not reject H0. There is not sufficient evidence to support the hypothesis that the
sequence is not random.
Q. 8Solar energy is considered by many to be the energy of the future. A recent survey was taken to compare the cost of solar energy to the cost of gas or electric energy.
Results of the survey revealed that the distribution of the amount of the monthly utility bill of a 3-bedroom house using gas or electric energy had a mean of 117 and a standard deviation of 13. If the distribution can be considered bell shaped, what percentage of homes will have a monthly utility bill of more than 104? A) approximately 84 B) approximately 95
C) approximately 16 D) approximately 32
Q. 9The Kruskal-Wallis test is the nonparametric version of the parametric _________.
A) One-way ANOVA test
B) linear correlation of variable
C) small sample z or t test
D) inference test about the difference of the means for independent samples
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