BSTAT FINAL EXAM QUESTIONS
AND 100% CORRECT ANSWERS!!
Find the following probabilities based on the standard normal variable
Z. a.P(Z > 0.94)
b.P(Z ≤ −2.08)
c.P(0 ≤ Z ≤ 1.32)
d.P(−0.93 ≤ Z ≤ 2.68)
a. .1736
b. .0188
c. .4066
d. .8201
The probability that a normal random variable is less than its mean is ______.
.5
A continuous random variable is characterized by uncountable values and can take on
any value within an interval.
T
Let X be normally distributed with mean µ = 25 and standard deviation σ = 5. Find the
value x such that P(X ≥ x) = 0.1736.
29.70
The probability density function of a continuous random variable is the counterpart to
the probability mass function of a discrete random variable.
T
Gold miners in Alaska have found, on average, 12 ounces of gold per 1,000 tons of dirt
excavated with a standard deviation of 3 ounces. Assume the amount of gold found per
, 1,000 tons of dirt is normally distributed.
What is the probability the miners find more than 16 ounces of gold in the next 1,000
tons of dirt excavated?
.0912
Let X be normally distributed with mean μ = 143 and standard deviation σ = 34.
a. Find P(X ≤ 100).
b. Find P(95 ≤ X ≤ 110).
c. Find x such that P(X ≤ x) = 0.370.
d. Find x such that P(X > x) = 0.890.
a. .1038
b. .0867
c. 131.712
d. 101.282
If X has a normal distribution with µ = 100 and σ = 5, then the probability P(90 ≤ X ≤ 95)
can be expressed in terms of a standard normal variable Z as ______.
P(-2 ≤ Z ≤ -1)
A young investment manager tells his client that the probability of making a positive return
with his suggested portfolio is 78%. If it is known that returns are normally distributed
with a mean of 4.3%, what is the risk, measured by standard deviation, that this
investment manager assumes in his calculation?
standard deviation= 5.570
Sarah's portfolio has an expected annual return at 8%, with an annual standard deviation
at 12%. If her investment returns are normally distributed, then in any given year Sarah
has an approximate ______.
50% chance that the actual return will be greater than 8%
The average rent in a city is $1,410 per month with a standard deviation of $290.
Assume rent follows the normal distribution.
AND 100% CORRECT ANSWERS!!
Find the following probabilities based on the standard normal variable
Z. a.P(Z > 0.94)
b.P(Z ≤ −2.08)
c.P(0 ≤ Z ≤ 1.32)
d.P(−0.93 ≤ Z ≤ 2.68)
a. .1736
b. .0188
c. .4066
d. .8201
The probability that a normal random variable is less than its mean is ______.
.5
A continuous random variable is characterized by uncountable values and can take on
any value within an interval.
T
Let X be normally distributed with mean µ = 25 and standard deviation σ = 5. Find the
value x such that P(X ≥ x) = 0.1736.
29.70
The probability density function of a continuous random variable is the counterpart to
the probability mass function of a discrete random variable.
T
Gold miners in Alaska have found, on average, 12 ounces of gold per 1,000 tons of dirt
excavated with a standard deviation of 3 ounces. Assume the amount of gold found per
, 1,000 tons of dirt is normally distributed.
What is the probability the miners find more than 16 ounces of gold in the next 1,000
tons of dirt excavated?
.0912
Let X be normally distributed with mean μ = 143 and standard deviation σ = 34.
a. Find P(X ≤ 100).
b. Find P(95 ≤ X ≤ 110).
c. Find x such that P(X ≤ x) = 0.370.
d. Find x such that P(X > x) = 0.890.
a. .1038
b. .0867
c. 131.712
d. 101.282
If X has a normal distribution with µ = 100 and σ = 5, then the probability P(90 ≤ X ≤ 95)
can be expressed in terms of a standard normal variable Z as ______.
P(-2 ≤ Z ≤ -1)
A young investment manager tells his client that the probability of making a positive return
with his suggested portfolio is 78%. If it is known that returns are normally distributed
with a mean of 4.3%, what is the risk, measured by standard deviation, that this
investment manager assumes in his calculation?
standard deviation= 5.570
Sarah's portfolio has an expected annual return at 8%, with an annual standard deviation
at 12%. If her investment returns are normally distributed, then in any given year Sarah
has an approximate ______.
50% chance that the actual return will be greater than 8%
The average rent in a city is $1,410 per month with a standard deviation of $290.
Assume rent follows the normal distribution.
