MAS 291 EXAM ALL QUESTIONS AND 100%
CORRECT ANSWERS!!
If X is a continuous random variable, then
c. P(x < X <x ) = P(x ≤ X<x ) = P(x < X ≤ x ) = P(x ≤ X ≤ x )
If we know that the length of time it takes a college student to find a parking spot in the
library parking lot follows a normal distribution with a mean of 3.5 minutes and a
standard
b. 0.3085
The probability density function of X, the time it takes a hematology cell counter to
complete a test on a blood sample is f(x)=0.05 for 60 < x < 80 . Find E(X) and V(X).
e. 70 and 33.33
Transactions to a computer database are either new items or changes to previous items.
The addition of an item can be completed in less than 100 milliseconds 80% of the time,
b. 0.65
The mean water temperature downstream from a power plant cooling tower discharge pipe
should be no more than 100°F. Past experience has indicated that the standard deviation of
temperature is 2°F. The water temperature is measured on nine randomly chosen days,
and
e. 0.99865
Eight measurements were made on the inside diameter of forged piston rings used in an
automobile engine. The data (in millimeters) are 74.10; 74.30; 74.15; 74.00; 74.25; 74.20
d. 74.14875
An article describles the effect of delamination on the natural frequency of beams made
from composite laminates. Five such delaminated beams were subjected to loads, and the
b. None of the other choices is correct
,A lot contains 15 castings from a local supplier and 35 castings from a supplier in the next
state. Two castings are selected randomly, without replacement, from the lot of 50. Let A
be the event that the first casting selected is from the local supplier and let B denote the
event
d. 0.375 and 0.1346
Retrospective Study, observational study and designed experiment are three basis methods
of
a. collecting datab. analyzing data
A normal population has mean 96 and variance 14. How large must be the random sample
be if we want the standard error of the sample mean to be 1.5
a. 7
The nine measurements that follow are furnace temperatures recorded on successive
batches in a semiconductor manufacturing process (units are ⁰F): 920, 918, 922, 930, 915,
921,925, 931, 927.
b. 923.22 and 29.44
The compressive strength of concrete is normally distributed with µ=1200 psi and a . A
random sample of n=9 specimens will have a sample mean diameter that falls in the
interval
from 1011 psi to 1230 psi. what is the standard error of the sample mean
d. 10
Suppose X has a hypergeometric distribution with N=20, n=4, and K=4. Find P(X=3) and
P(X ≤ 3)
d. 0.0132 and 0.99998
Let != be "not equal to". The heat evolved in calories per gram of a cement mixture is
approximately normally distributed. The mean is thought to be 100 and the standard
deviation is 2.
, b. 0.0027
Let X be a continuous uniform distribution over the interval [2.4; 5.2].
d. 3.8 and 0.808
What is a method of collecting data
c. A retrospective study using historical data.
Suppose data is obtained from 20 pairs of (x,y) and the sample correlation coefficient is 0.9.
a. Reject H₀ .
A normal population has mean 76 and variance 9. How large must be the random sample
be if we want the standard error of the sample mean to be 1.1
e. 8
A random sample of n=25 observations was made on the time to failure of an electronic
component and the temperature in the application environment in which the component
was
a. Reject H₀ .
An economist is interested in studying the incomes of consumers in a particular region. The
population standard deviation is known to be USD1000. A random sample of 50 individuals
resulted in an average income of USD15000. What total sample size would the economist
b. n = 385
Some fields in statistics:
b. the collection, presentation, analysis and use of data to make decisions, solve
problems.
An engineer who is studying the tensile strength of a steel alloy intended for use in golf club
shafts knows that tensile strength is approximately normally distributed with standard
deviation 50 psi.
CORRECT ANSWERS!!
If X is a continuous random variable, then
c. P(x < X <x ) = P(x ≤ X<x ) = P(x < X ≤ x ) = P(x ≤ X ≤ x )
If we know that the length of time it takes a college student to find a parking spot in the
library parking lot follows a normal distribution with a mean of 3.5 minutes and a
standard
b. 0.3085
The probability density function of X, the time it takes a hematology cell counter to
complete a test on a blood sample is f(x)=0.05 for 60 < x < 80 . Find E(X) and V(X).
e. 70 and 33.33
Transactions to a computer database are either new items or changes to previous items.
The addition of an item can be completed in less than 100 milliseconds 80% of the time,
b. 0.65
The mean water temperature downstream from a power plant cooling tower discharge pipe
should be no more than 100°F. Past experience has indicated that the standard deviation of
temperature is 2°F. The water temperature is measured on nine randomly chosen days,
and
e. 0.99865
Eight measurements were made on the inside diameter of forged piston rings used in an
automobile engine. The data (in millimeters) are 74.10; 74.30; 74.15; 74.00; 74.25; 74.20
d. 74.14875
An article describles the effect of delamination on the natural frequency of beams made
from composite laminates. Five such delaminated beams were subjected to loads, and the
b. None of the other choices is correct
,A lot contains 15 castings from a local supplier and 35 castings from a supplier in the next
state. Two castings are selected randomly, without replacement, from the lot of 50. Let A
be the event that the first casting selected is from the local supplier and let B denote the
event
d. 0.375 and 0.1346
Retrospective Study, observational study and designed experiment are three basis methods
of
a. collecting datab. analyzing data
A normal population has mean 96 and variance 14. How large must be the random sample
be if we want the standard error of the sample mean to be 1.5
a. 7
The nine measurements that follow are furnace temperatures recorded on successive
batches in a semiconductor manufacturing process (units are ⁰F): 920, 918, 922, 930, 915,
921,925, 931, 927.
b. 923.22 and 29.44
The compressive strength of concrete is normally distributed with µ=1200 psi and a . A
random sample of n=9 specimens will have a sample mean diameter that falls in the
interval
from 1011 psi to 1230 psi. what is the standard error of the sample mean
d. 10
Suppose X has a hypergeometric distribution with N=20, n=4, and K=4. Find P(X=3) and
P(X ≤ 3)
d. 0.0132 and 0.99998
Let != be "not equal to". The heat evolved in calories per gram of a cement mixture is
approximately normally distributed. The mean is thought to be 100 and the standard
deviation is 2.
, b. 0.0027
Let X be a continuous uniform distribution over the interval [2.4; 5.2].
d. 3.8 and 0.808
What is a method of collecting data
c. A retrospective study using historical data.
Suppose data is obtained from 20 pairs of (x,y) and the sample correlation coefficient is 0.9.
a. Reject H₀ .
A normal population has mean 76 and variance 9. How large must be the random sample
be if we want the standard error of the sample mean to be 1.1
e. 8
A random sample of n=25 observations was made on the time to failure of an electronic
component and the temperature in the application environment in which the component
was
a. Reject H₀ .
An economist is interested in studying the incomes of consumers in a particular region. The
population standard deviation is known to be USD1000. A random sample of 50 individuals
resulted in an average income of USD15000. What total sample size would the economist
b. n = 385
Some fields in statistics:
b. the collection, presentation, analysis and use of data to make decisions, solve
problems.
An engineer who is studying the tensile strength of a steel alloy intended for use in golf club
shafts knows that tensile strength is approximately normally distributed with standard
deviation 50 psi.
