Chapter 2 Test Materials Flashcards
If ABC Company wants to assess how it has changed its own products prices for the past five years, which of the following would be useful:
a. ABC’s price listing at end of year for past five years
b. ABC’s average price over the past five years
c. Major competitor prices at end of year for the past five years
d. ABC’s year end price with the industry average price in the current year
A
Although most people often use this statistical tool, they usually refer to it as the “average rather than the statistical term which is the
Mean
TRUE OR FALSE: The median is the observed value that is in the center position hierarchically, among the observed values in a data set
True
When a company evaluates its past three years of financial results, it often uses the data to plan future revenue and expenses. If the past three years of data indicate a trend of 3% annual increases in revenue, the ____________ value for the next year is likely to be 3% higher than the current year
Expected
The standard deviation is used to determine:
a. The sum of the squared differences between observed values and the mean
b. the sum of squared differences divided by the number of observations
c. the sum of squared differences divided by the number of observations divided by n -1
d. the increment of probability differences on a Z-tables (or using NORMSDIST in Excel
D
If the mean of a standard Normal distribution is 500 and the standard deviation is 50, what would be the upper and lower limits for the central location of 95.44% of the distribution?
Upper: 600
Lower: 400
The symbol for the mean of a population is (mu) and the symbol of the mean for a sample is x-bar. The symbol for a population proportion is P, what is the symbol for a sample proportion
p–hat
Which of the following data sets is most likely to represent the shape of a standard Normal distribution
a. 500 records of retail sales in a store
b. 30 records of customer preferences for candy
c. 900 records for measurements of rainfall in a day
d. 2000 records for a mean in different samples of the same population
D
TRUE OR FALSE: Multiple samples from the same population will yield different results
True
TRUE OR FALSE: Computer programs are used to simulate the process of performing hundreds of samples in order to understand the range of differences among samples
True
Calculating the standard deviation for differences in proportions among different samples of the same population in
a. defining the upper limits of the tail
b. defining the lower limits of the tail
c. identifying where 68.25% and 95.44% of the distribution are located
d. None of the above
C
The z-value of 1.5 corresponds to which of the following:
a. -2.5 (mu)
b. -1.5 standard deviation
c. -1.5 x-bar
d. + 1.5 standard deviation
D
The area of the curve above 1.96 standard deviation represents what percentage of the entire distribution?
a. 5%
b. 2.5%
c. 2.28%
d. 2.15%
B
If the probability of a z-value of -1.5 =0.0668, what is the probability of a value in a standard Normal distribution being between a z-value of -1.5 and the mean of the distribution
a. 0.4332
b. 0.4443
c. 0.5432
d. 0.4123
A
What do statisticians call the standard deviation of the sampling distribuion?
a. the square root
b. the standard error
c. the margin of extremes
d. sample stress
B
Standard error (SE) may be calculated for which of the following:
a. the mean of multiple samples
b. a proportion of interest to researchers
c. both a and b
d. neither a or b
C
Which of the following confidence intervals has the widest numeric range?
a. 99% confidence level
b. 95% confidence level
c. 90% confidence level
d. 68% confidence level
A
TRUE OR FALSE: The alternative hypothesis states the alternative outcome, assuming the null hypothesis can not be accepted
True
In the space below immediately below, write the pair used to test whether results are neither higher or lower than some hypothesized value
Two Tailed test
In the space immediately below, write the pair of hypotheses used to test situations when there is concern or expectation about values being higher than some value
Upper Tail test
In the space immediately below, write the pair of hypotheses used to test situations when there is concern or expectation about values being lower than some value
Lower Tail
Standard error(SE) is a computer simulation of which of the following:
a. the standard deviation of the mean of a sample
b. the standard deviation of the mean of over 100 samples
c. the mean of a sample
d. the mean of a random sample
B
In hypothesis testing where the standard deviation of the population is known, we often test to verify that the sample mean is not less than some value. Is this a one or two -tailed test?
One tailed
If we are mainly concerned about identifying observed values below some range, would the test be a lower tail or upper tail
Lower Tail
In hypothesis tests where the standard deviation of the population is known, we sometimes test to verify that the sample mean is not different than some specific value. Is this a one-tail or a two tail test
Two-Tail
TRUE OR FALSE: Standard Error (SE) is the estimate of variation among multiple samples called the sampling distribution
TRUE
TRUE OR FALSE: If you know one standard deviation of the population and the number of observations that are in a sample you can calculate SE of the sampling distribution with the formula
True
If an organization routinely performs hypothesis tests of some repeated process, is it likely that hundreds of tests would be conducted over several years and that the range of the values would be known
Yes
If an organization retains the data from hundreds of tests of some process, is it likely that the organizations’s testers have developed reliable standard deviations for the most commonly measured processes
Yes
If the z-value of a test statistic in a lower tail test with a 5 % alpha is -2.67, would this be sufficiently low to rejected the null hypothesis
Yes
In a one-tail test, if you use the p-value approach in deciding whether to accept or reject a null hypothesis, you will reject the H0 if the p-value of the test statistic is less the probability of:
a. the probability of the alpha in whichever tail is being tested
b. the z-value of the alpha in the upper tail
c. the z-value of the alpha in the lower tail
d. one half of the alpha
A
If we reflect a null hypothesis, what do we do with the HA
Accept it
TRUE OR FALSE: Choosing a numerically higher confidence interval, and therefor a numerically lower alpha, widens the range of values defined as acceptable in the hypotheses
TRUE
