If we change a 95% confidence interval estimate to a 99% confidence interval estimate,
we can expect the
a. width of the confidence interval to increase
b. width of the confidence interval to decrease
c. width of the confidence interval to remain the same
d. sample size to increase
Exhibit 14-4
The following information regarding a dependent variable (Y) and an independent
variable (X) is provided.
SSE = 6
SST = 16
Refer to Exhibit 14-4. The least squares estimate of the slope is
a. 1
b. 2
c. 3
d. 4
The price of a stock is uniformly distributed between $30 and $40.
a. What is the probability that the stock price will be more than $37?
b. What is the probability that the stock price will be less than or equal to $32?
c. What is the probability that the stock price will be between $34 and $38?
d. Determine the expected price of the stock.
e. Determine the standard deviation for the stock price.
The U.S. Census Bureau conducts a census every
a. 4 years
b. 5 years
c. 8 years
d. 10 years
Exhibit 16-2
In a regression model involving 30 observations, the following estimated regression
equation was obtained.
= 170 + 34x1 – 3x2 + 8x3 + 58x4 + 3x5
For this model, SSR = 1,740 and SST = 2,000.
Refer to Exhibit 16-2. The value of MSE is
a. 348
b. 10.40
c. 10.83
d. 32.13
If the coefficient of determination is equal to 1, then the coefficient of correlation
a. must also be equal to 1
b. can be either -1 or +1
c. can be any value between -1 to +1
d. must be -1
Posterior probabilities are computed using
a. the classical method
b. Chebyshev’s theorem
c. the empirical rule
d. Bayes’ theorem
The numerical value of the coefficient of determination
a. is always larger than the coefficient of correlation
b. is always smaller than the coefficient of correlation
c. is negative if the coefficient of determination is negative
d. can be larger or smaller than the coefficient of correlation
Excel’s POISSON.DIST function can be used to compute
a. bin width for histograms
b. Poisson probabilities
c. cumulative Poisson probabilities
d. Both Poisson probabilities and cumulative Poisson probabilities are correct.
A fashion designer wants to produce a new line of clothes. In the production of the
clothes, expensive, medium-priced, or inexpensive materials can be used. The profit
associated with each type of material depends upon economic conditions next year.
Below you are given the payoff table.
An economist believes that the probability that the economy will improve is 20%, the
probability that the economy will stay the same is 70%, and the probability that the
economy will get worse is 10%.
A sample of five Fortune 500 companies showed the following industry codes: banking,
banking, finance, retail, and banking. Based on this information, which of the following
statements is correct?
a. Sixty percent of the sample of five companies are banking industries.
b. Sixty percent of all Fortune 500 companies are banking industries.
c. Banking is the most common type of industry among all Fortune 500 companies.
d. If five other Fortune 500 companies were chosen, 60% of them would be banking
industries.
During a cold winter, the temperature stayed below zero for ten days (ranging from -20
to -5). The variance of the temperatures of the ten day period
a. is negative since all the numbers are negative
b. must be at least zero
c. cannot be computed since all the numbers are negative
d. can be either negative or positive
In a completely randomized experimental design, 18 experimental units were used for
the first treatment, 10 experimental units for the second treatment, and 15 experimental
units for the third treatment. Part of the ANOVA table for this experiment is shown
below.
As the sample size increases, the variability among the sample means
a. increases
b. decreases
c. remains the same
d. depends upon the specific population being sampled
Exhibit 2-3
The number of sick days taken (per month) by 200 factory workers is summarized
below.
Refer to Exhibit 2-3. The midpoint of the first class is
a. 10
b. 2
c. 2.5
d. 3
In a multiple regression analysis involving 10 independent variables and 81
observations, SST = 120 and SSE = 42. The coefficient of determination is
a. 0.81
b. 0.11
c. 0.35
d. 0.65
For the Excel worksheet above, which of the following formulas would correctly
calculate the joint probability for cell D3?
a. =SUM(B3:C3)
b. B3+C3
c. B3/C3
d. =B3*C3
Ten administrative assistants were sent to take a typing efficiency course. The following
data show the typing speeds of the administrative assistants before and after the course.
At = 0.05, what can be concluded about the effectiveness of the course?
A national poll reported that 58% of those with Internet access have made purchases
online. To investigate whether this percentage applies to its own state, a legislator
commissions a study. A random sample of 400 state residents who have Internet access
is taken. Of those 400 respondents, 215 said that they have made purchases online.
Does this sample provide sufficient evidence to conclude that the state differs from the
nation with respect to making purchases online? Use the p-value to conduct the
hypothesis test and use a .05 level of significance.
The yearly series below exhibits a long-term trend. Use the appropriate forecasting
technique to produce forecasts for years 11 and 12.
The data below shows samples of annual salaries (in thousands of dollars) for
accountants in two different firms.
Use Excel to determine whether the variance in salaries in Company A differs from than
that of Company B? Use a .10 level of significance.
Two hundred members of a fitness center were surveyed. One survey item stated, “The
facilities are always clean.” The members’ responses to the item are summarized below.
Fill in the missing value for the frequency distribution.
A random sample of 26 checking accounts at a bank showed an average daily balance
of $300 and a standard deviation of $45. The balances of all checking accounts at the
bank are normally distributed. Develop a 95% confidence interval estimate for the mean
of the population.