MGSC 291 Exam 1 Study Guide Latest
update 2025/2026
The ________ is a graphic that is used to visually check whether data come from a
normal population.
exponential plot
normal probability plot
box-and-whiskers plot
normal distribution graph - correct answernormal probability plot
It is appropriate to use the uniform distribution to describe a continuous random variable
x when
the area under the probability curve = 1.
the probability curve f(x) > 0.
the shape of the histogram of all possible values of x is nonsymmetrical.
relative frequencies of all possible values of x are about the same. - correct answerd.
relative frequencies of all possible values of x are about the same.
The normal approximation of the binomial distribution is appropriate when np≥ 5.
n(1 −p) ≥ 5.
np≤ 5.
n(1 −p) ≤ 5 and np≤ 5.
np≥ 5 and n(1 −p) ≥ 5. - correct answernp≥ 5 and n(1 −p) ≥ 5.
The fill weight of a certain brand of adult cereal is normally distributed with a mean of
910 grams and a standard deviation of 5 grams. We calculated the value of z for a
specific box of this brand of cereal, and the z value was negative. This negative z value
indicates that
we made a mistake in our calculations, as z must always be a nonnegative number.
the fill weight is more than 910 grams.
the fill weight is less than 910 grams.
the fill weight is equal to 910 grams.
the fill weight may be more or less than 910 grams depending on the value of the
standard deviation. - correct answerthe fill weight is less than 910 grams.
Which of the following statements is not a property of the normal probability distribution?
The normal distribution is symmetric.
, 95.44 percent of all possible observed values of the random variable x are within plus or
minus three standard deviations of the population mean.
The mean, median, and mode are equal.
The area under the normal curve to the right of the mean is equal to the area under the
normal curve to the left of the mean.
All of these answers are properties of the normal distribution. - correct answer95.44
percent of all possible observed values of the random variable x are within plus or
minus three standard deviations of the population mean.
If the random variable x is normally distributed, ______ percent of all possible observed
values of x will be within three standard deviations of the mean.
68.26
95.44
99.73
100 - correct answer99.73
The z value tells us the number of ________ that a value of x is from the mean.
variances
standard deviations
medians
standard means - correct answerstandard deviations
A continuous probability distribution having a rectangular shape, where the probability is
evenly distributed over an interval of numbers is a(n) ________ distribution.
exponential
binomial
normal
uniform - correct answeruniform
The specific shape of each normal distribution is determined by its ________ and
________.
mean, standard deviation.
median, standard deviation
mean, variance
median, variance - correct answermean, standard deviation.
The area under the curve of a valid continuous probability distribution must ________.
equal 1
be between 0 and 1
be infinite
be less than 1 - correct answerequal 1
update 2025/2026
The ________ is a graphic that is used to visually check whether data come from a
normal population.
exponential plot
normal probability plot
box-and-whiskers plot
normal distribution graph - correct answernormal probability plot
It is appropriate to use the uniform distribution to describe a continuous random variable
x when
the area under the probability curve = 1.
the probability curve f(x) > 0.
the shape of the histogram of all possible values of x is nonsymmetrical.
relative frequencies of all possible values of x are about the same. - correct answerd.
relative frequencies of all possible values of x are about the same.
The normal approximation of the binomial distribution is appropriate when np≥ 5.
n(1 −p) ≥ 5.
np≤ 5.
n(1 −p) ≤ 5 and np≤ 5.
np≥ 5 and n(1 −p) ≥ 5. - correct answernp≥ 5 and n(1 −p) ≥ 5.
The fill weight of a certain brand of adult cereal is normally distributed with a mean of
910 grams and a standard deviation of 5 grams. We calculated the value of z for a
specific box of this brand of cereal, and the z value was negative. This negative z value
indicates that
we made a mistake in our calculations, as z must always be a nonnegative number.
the fill weight is more than 910 grams.
the fill weight is less than 910 grams.
the fill weight is equal to 910 grams.
the fill weight may be more or less than 910 grams depending on the value of the
standard deviation. - correct answerthe fill weight is less than 910 grams.
Which of the following statements is not a property of the normal probability distribution?
The normal distribution is symmetric.
, 95.44 percent of all possible observed values of the random variable x are within plus or
minus three standard deviations of the population mean.
The mean, median, and mode are equal.
The area under the normal curve to the right of the mean is equal to the area under the
normal curve to the left of the mean.
All of these answers are properties of the normal distribution. - correct answer95.44
percent of all possible observed values of the random variable x are within plus or
minus three standard deviations of the population mean.
If the random variable x is normally distributed, ______ percent of all possible observed
values of x will be within three standard deviations of the mean.
68.26
95.44
99.73
100 - correct answer99.73
The z value tells us the number of ________ that a value of x is from the mean.
variances
standard deviations
medians
standard means - correct answerstandard deviations
A continuous probability distribution having a rectangular shape, where the probability is
evenly distributed over an interval of numbers is a(n) ________ distribution.
exponential
binomial
normal
uniform - correct answeruniform
The specific shape of each normal distribution is determined by its ________ and
________.
mean, standard deviation.
median, standard deviation
mean, variance
median, variance - correct answermean, standard deviation.
The area under the curve of a valid continuous probability distribution must ________.
equal 1
be between 0 and 1
be infinite
be less than 1 - correct answerequal 1
