WEEK 2 LearnSmart - Busi 2305
Which of the following statements best describes the strength of the range as a measure of dispersion?
The calculation in easy to perform.
Dot plots allow one to observe which of the following?
The center of a distribution. The shape of a distribution. The spread in a distribution.
Suppose a given data set has the following characteristics: Minimum value: 120 Q1: 160 Q2: 190 Q3: 200 Maximum Value: 220 Which of the following is true about the distribution of the data?
The distribution is negatively skewed.
The dispersion of a set of data is often referred to as which of the following?
variation or spread
Match the proportion of observations below the measure to the measure of position.
1/2 - median 4/5 - 8th decile 3/4 - 3rd quartile 1/5 20th percentile
Match the measure of position to the number of parts into which it divides a set of observations.
100 - percentiles 10 - deciles 4 - quartiles 2 - median
Suppose a population is made up of the following values: 1, 8, 5, 6. What is the population mean?
5 reason: (1+8+5+6)/4=20/4=5
Which of the following is true regarding the application of Chebyshev's theorem and the Empirical Rule?
Only Chebyshev's applies to skewed distributions. The Empirical Rule gives more precise answers for the symmetrical, bell-shaped distribution.
Which of the following are used to measure dispersion?
Range Variance Standard Deviation
The formula for the weighted mean is Xw=Σ(wX)/Σw Which of the following statements are true of the weighted mean?
The denominator of the weighted mean is always the sum of the weights. It is used with data that has repeated values, such as a frequency distribution.
The interquartile range is a measure of dispersion usually used along with the median. What is the definition of interquartile range?
The distance between the first and third quartile.
A dot plot would be appropriate to display which one of the following kinds of data?
a small set of data.
It is appropriate to remove outliers in the data set to make the data easier to analyze.
false
The variance is a measure of central tendency.
false
Contingency tables are used for summarizing data of what level?
ordinal nominal
Which one of the following formulas is Pearson's Coefficient of Skewness?
sk=3(X−Median)/s
Which one of the following formulas is the Software Coefficient of Skewness?
sk=n/(n−1)(n−2)*[Σ(x−xs)3]
The Population Mean is:
the arithmetic mean of all of the values in the population
The Empirical rule states approximately what percentage of observations will be found within some deviation from the mean for a normal distribution. Match the percentage of observation to the range.
68% - plus or minus one standard deviation. 95% - plus or minus two standard deviations. 99.7% - plus or minus three standard deviations.
Suppose the wait time at the emergency room follow a symmetrical, bell-shaped distribution with a mean of 90 minutes and a standard deviation of 10 minutes. What percentage of emergency room patients will wait between 1 hour and 2 hours?
99.7%
What is the definition of "parameter"?
A characteristic of a population.
Which of the following statements represent an ethical approach to the use of statistics?
A statistical report requires objective and honest communication of results. We must maintain an independent and principled point of view.
Identify the correct statements regarding the application of Chebyshev's theorem and the Empirical Rule.
Chebyshev's theorem applies to any set of values. Chebyshev's theorem works for symmetrical, bell-shaped distributions.
Which one of the following pairs of variables would be best-suited for a contingency table?
Favorite color and gender
What statements below describe the relative use of dot plots and histograms?
Histograms are more useful for large data sets. Dot plots are most useful for small data sets.
The formula for the weighted mean is Xw=Σ(wX)/Σw Which of the following statements are true of the weighted mean?
It is a special case of the arithmetic mean. The denominator of the weighted mean is always the sum of the weights. It is used when there are several observations of the same value.
Which of the following statements describe weaknesses of the range as a measure of dispersion?
It may be unduly influenced by an especially small value. Only two values from the data set are used. It may be unduly influenced by an unusually large value
How do you find the Population Mean for a set of data?
Sum the values in the population and then divide by the number of values in the population.
Which of the following is a population parameter if you are investigating the average age of patients at a local hospital?
The ages of all of the patients at a local hospital.
Choose the best definition for the variance.
The arithmetic average of the squared deviations from the mean.
