CHECK MCQ PART A CORRECT 100%
The distribution of heights for adult men in a certain population is approximately normal
with mean 70 inches and standard deviation 4 inches. Which of the following represents
the middle 80 percent of the heights? - ANSWER64.87 inches to 75.13 inches
The distribution of the amount of water used per wash cycle, in gallons, by a particular
brand of dishwasher during a wash cycle is approximately normal with mean 4 gallons
and standard deviation 0.2 gallon. Which of the following is closest to the probability that
more than 3.75 gallons are used for any wash cycle? - ANSWER0.89
The life span of a battery is the amount of time the battery will last. The distribution of
life span for a certain type of battery is approximately normal with mean 2.5 hours and
standard deviation 0.25 hour. Suppose one battery will be selected at random. Which of
the following is closest to the probability that the selected battery will have a life span of
at most 2.1 hours? - ANSWER0.055
Data were collected on the following variables. Which variable is LEAST likely to be
approximated with a normal model? - ANSWERThe distribution of ages, in years, of all
the residents of a town, where the right tail of the distribution is longer than the left
An online news source reports that the proportion of smartphone owners who use a
certain operating system is 0.216. Two simulations will be conducted to create a
sampling distribution of the sample proportion from a population with proportion 0.216.
Simulation A will consist of 1,000 trials with a sample size of 50. Simulation B will
consist of 500 trials with a sample size of 100.
Which of the following describes the centers and variabilities that should be apparent in
the distributions generated by simulation A and simulation B? - ANSWERThe centers
will be approximately equal, and the variability of simulation A will be greater than the
variability of simulation B.
Samples A and B were selected from the same population. The mean of sample A is
equal to the mean of the population.
Which of the following statements must be true?
The mean of sample A is a point estimator for the mean of the population.
The mean of sample B is a point estimator for the mean of the population.
The mean of sample A is equal to the mean of sample B. - ANSWERII and III
The statistic s is used as an estimator for which of the following? - ANSWERσ
A certain statistic will be used as an unbiased estimator of a parameter. Let R represent
the sampling distribution of the estimator for samples of size 35, and let S represent the
sampling distribution of the estimator for samples of size 15.