Engineering Pathfinder - Engineering
Statistics III
Which is the Two-Sided Confidence Interval? - CORRECT ANSWER-(L < μ < U)
with __ % Confidence
Which is the Sample Size? - CORRECT ANSWER-n
The fuel efficiency of a new car is tested, resulting in a 2-side confidence interval
of (45.6 mpg ≤ μ ≤ 51.1 mpg) with 95 % Confidence. Which conclusion is
correct? - CORRECT ANSWER-The car's fuel efficiency is not significantly
different than 50 mpg, at a confidence level of 95%
A new battery is expected to have a storage capacity of 60 ampere-hour (A h). A
sample is tested, resulting in a 2-side confidence interval of (55 A h ≤ μ ≤ 65 A h)
with 97.5 % Confidence. Which conclusion is correct? - CORRECT
ANSWER-The battery storage capacity is not significantly different than 60 A h,
at a confidence level of 97.5 %
Two deposits of coal are expected to have different energy content (per ton).
Samples of the two type are tested to determine their means, standard
deviations, and standard errors of the mean. The two means are compared using
error bars that are twice the standard error of the mean. What does it mean if the
bars overlap? - CORRECT ANSWER-The mean energy contents ARE NOT
different in a statistically significant way
Two water pipes are expected to burst at different pressures. Samples of the two
type are tested to determine their means, standard deviations, and standard
errors of the mean. The two means are compared using error bars that are the
95 % confidence interval. What does it mean if the bars overlap? - CORRECT
ANSWER-No statistical inference can be made
(AFTER QUESTIONS - 2 sided CI - mean (first one), parts 1-3)
X (mean) = 201.3
s (standard dev) = 19.7
Statistics III
Which is the Two-Sided Confidence Interval? - CORRECT ANSWER-(L < μ < U)
with __ % Confidence
Which is the Sample Size? - CORRECT ANSWER-n
The fuel efficiency of a new car is tested, resulting in a 2-side confidence interval
of (45.6 mpg ≤ μ ≤ 51.1 mpg) with 95 % Confidence. Which conclusion is
correct? - CORRECT ANSWER-The car's fuel efficiency is not significantly
different than 50 mpg, at a confidence level of 95%
A new battery is expected to have a storage capacity of 60 ampere-hour (A h). A
sample is tested, resulting in a 2-side confidence interval of (55 A h ≤ μ ≤ 65 A h)
with 97.5 % Confidence. Which conclusion is correct? - CORRECT
ANSWER-The battery storage capacity is not significantly different than 60 A h,
at a confidence level of 97.5 %
Two deposits of coal are expected to have different energy content (per ton).
Samples of the two type are tested to determine their means, standard
deviations, and standard errors of the mean. The two means are compared using
error bars that are twice the standard error of the mean. What does it mean if the
bars overlap? - CORRECT ANSWER-The mean energy contents ARE NOT
different in a statistically significant way
Two water pipes are expected to burst at different pressures. Samples of the two
type are tested to determine their means, standard deviations, and standard
errors of the mean. The two means are compared using error bars that are the
95 % confidence interval. What does it mean if the bars overlap? - CORRECT
ANSWER-No statistical inference can be made
(AFTER QUESTIONS - 2 sided CI - mean (first one), parts 1-3)
X (mean) = 201.3
s (standard dev) = 19.7
