Exam 4: Numerical Descriptive Techniques

NARRBEGIN: Experience and Salary Longevity and Salary A sample of eight observations of variables x (years of experience) and y (salary in $1,000s) is shown below: 5 3 7 9 2 4 6 y 20 23 15 11 27 21 17 14 NARREND -{Longevity and Salary Narrative} a.Calculate the coefficient of correlation, and comment on the relationship between x and y. b.Give a possible reason that the correlation is negative.

Which of the following is a characteristic of graphical excellence?

Which of the following types of data has no measure of variability?

You are less likely to be misled by a graph if you:

Suppose that a firm's sales were $3,750,000 five years ago and are $5,250,000 today. What was the geometric mean growth rate in sales over the past five years?

NARRBEGIN: Hours of Playing Video Ga Hours of Playing Video Games Suppose that the following data provide the hours of playing video games per week for a sample of 15 high school students in Roanoke, Virginia: 5, 11, 25, 19, 18, 20, 27, 13, 8, 10, 15, 19, 18, 9, and 12.NARREND -{Hours of Playing Video Games Narrative} Determine the location and value of the third quartile.

NARRBEGIN: Admission to ER Admission to ER The following bar chart shows the type of aspirin (if any) given to 100 cardiac patients within 15 minutes of their admission to the emergency room. NARREND -{Admission to ER Narrative} Notice that the Y-axis of the bar chart does not start at a frequency of zero. Create a new bar chart of the displayed data that accurately displays the frequency for each aspirin type.

NARRBEGIN: Salaries of Employees Salaries of Employees The following data represent the yearly salaries (in thousands of dollars) of a sample of 13 employees of a firm: 26.5, 23.5, 29.7, 24.8, 21.1, 24.3, 20.4, 22.7, 27.2, 23.7, 24.1, 24.8, and 28.2.NARREND -{Salaries of Employees Narrative} Compute the mean salary.

There are three measures of central location; the mean, the ____________________ and the ____________________.

A pie chart showing 80% yes and 20% no would look the same whether it was based on 10,000 observations or 10 observations. This is one way that pie charts can be deceptive.

NARRBEGIN: Milk Demand Milk Demand A supermarket has determined that daily demand for milk containers has an approximate bell shaped distribution, with a mean of 55 containers and a standard deviation of six containers.NARREND -{Milk Demand Narrative} How often can we expect between 49 and 61 containers to be sold in a day? (Give a percentage.)

NARRBEGIN: Admission to ER Admission to ER The following bar chart shows the type of aspirin (if any) given to 100 cardiac patients within 15 minutes of their admission to the emergency room. NARREND -{Admission to ER Narrative} In what way does the original bar chart distort the data as compared to a bar chart that starts at zero on the Y-axis (frequency axis)?

If the median, median and mode are all equal, the histogram must be symmetric and bell shaped.

The precision provided by the numerical techniques (mean, median, and standard deviation) provides more useful information than graphical techniques (histograms and box plots) alone.

Pie charts only show ____________________, not ____________________. This means you don't know what the sample size is unless it is stated on the pie chart.

The ____________________ of a linear relationship is hard to interpret from the covariance, but it is easy to interpret from the correlation.

In a bell shaped distribution, there is no difference in the values of the mean, median, and mode.

The middle line inside the box in a box plot represents the ____________________.

NARRBEGIN: Children Computers The following data represent the number of computers owned by a sample of 10 families from Chicago: 4, 2, 1, 1, 5, 3, 0, 1, 0, and 2.NARREND -{Computers Narrative} Compute the median number of computers.

The coefficient of variation is a measure of variability.