Which measure of dispersion (variation) is best used when a data set is known to be highly skewed?

Toward the back surface, another word for posterior is:

What is the best predicted shape of a data set if the mean is 100.4 and the median is 194?

Consider the following:A researcher obtained a random sample of 100 smokers and a random sample of 100 nonsmokers. After interviewing all 200 participants in the study and determining whether each was clinically depressed, the researcher compared the rate of depression among the smokers with the rate of depression among nonsmokers. Is this an observational or experimental study?  [exp]  Why?  [why]  What is the response variable?  [resp] What is the explanatory variable? [expl]

A certain college is concerned about grade inflation and decides to include z-scores along with letter grades for each class.  Suppose a certain student takes three classes.  The table below gives the students score in each class, along with the mean and standard deviation of the scores in each class.   Subject Student’s score Mean  Standard deviation  z-score Math 82 73.1 5.6 [math] English 75 70 3.4 [eng] History 91 84 4.7 [his] 1. Complete the table by finding the z-score for each class.  If rounding is necessary, round to two decimal places.  2. Complete the following sentence:  Relatively speaking the student did the best in [subj] because [reason]

Suppose the mean wait time for the Peter Pan ride at Disneyland is 39 minutes with a standard deviation of 12.5 minutes.   Assuming that the wait times are bell shaped, complete the following.  1. Approximately what percentage of wait times are at least 26.5 minutes?  [q1] 2. Approximately 68% of wait times are between ___________.  [q2] 3.   The longest 2.5% of wait times are ______________.[q3] 4. Approximately what percentage of wait times are between 26.5 minutes and 76.5 minutes?[q4]

Identify each of the following variables as qualitative, quantitative continuous, or quantitative discrete and then identify the appropriate level of measurement.  1. Number of languages spoken fluently.     a. [qual]     b. [lev] 2. Color of a soccer jersey    a. [qual2]    b. [level2]

Identify each of the following variables as qualitative, quantitative continuous, or quantitative discrete and then identify the appropriate level of measurement.  1. Rating of a pillow – soft, medium, hard     a. [qual]     b. [lev] 2. Number of books read during a summer reading program.    a. [qual2]    b. [level2]

On a recent road trip, a driver kept track of the price of gas at a sample of gas stations.  The observations are summarized in the table below. Price of a Gallon of Gas in Dollars Number of Stations $5.00 – $5.49 3 $5.50 – $5.99 7 $6.00 – $6.49 10 $6.50 – $6.99 12 $7.00 – $7.49 5 $7.50 – $7.99 2 Use this table to answer the following questions.  1. Estimate the mean and standard deviation for the price of a gallon of gas using this table.      Mean = [mean]  (rounded to two decimal places)      Std dev = [sd]  (rounded to three decimal places) 2. What is the class width of this table?   [width] 3. What is the relative frequency of the second class?  [rel]  (Rounded to three decimal places) 4. What is the best description of the shape of this data set?  [shape]

A study of all 2093 employees of a company shows that 54%  are satisfied with the company’s health care policy.  Is the underlined value a parameter or a statistic and why?