Stats chapter 2 online HW
________are sample values that lie very far away from the majority of the other sample values.
outliers
The histogram to the right represents the weights (in pounds) of members of a certain high-school programming team. How many team members are included in the histogram?
The histogram represents 18 programming team members. (the x-axis shows weight in pounds, but the y-axis is frequency)(you would count the frequency from each bar in the histogram to get total members).
Does the result appear to have a normal distribution? Why or why not?
Yes, because the frequencies start low comma reach a maximum comma then become low again, and are roughly symmetric about the maximum frequency.
Does the frequency distribution appear to have a normal distribution? Explain. Temperature_ (F) Frequency 35-39 1 40-44 3 45-49 10 50-54 12 55-59 10 60-64 2 65-69 1
Yes, because the frequencies start low, proceed to one or two high frequencies, then decrease to a low frequency, and the distribution is approximately symmetric.
The graph to the right uses cylinders to represent barrels of oil consumed by two countries. Does the graph distort the data or does it depict the data fairly? Why or why not? If the graph distorts the data, construct a graph that depicts the data fairly.
Yes, because the graph incorrectly uses objects of volume to represent the data.
Identify the class width and class midpoints. Height (inches) Frequency 59.0-61.9 4 62.0-64.9 25 65.0-67.9 9 68.0-70.9 1 71.0-73.9 0 74.0-76.9 0 77.0-79.9 0 80.0-82.9 0 83.0-85.9 0 86.0-88.9 1
a). What is the class width? 3 b.)What are the class midpoints? 60.45, 63.45, 66.45, 69.45 ,72.45 ,75.45, 78.45, 81.45,84.45, 87.45
Class width is found by _______.
subtracting a lower class limit from the next consecutive lower class limit
The graph to the right shows the braking distances for different cars measured under the same conditions. Describe the ways in which this graph might be deceptive. How much greater is the braking distance of Car A than the braking distance of Car C? Draw the graph in a way that depicts the data more fairly. a. In what way might the graph be deceptive? b. How much greater is the braking distance of Car A than the braking distance of Car C?
a. By starting the horizontal axis at 100, the graph cuts off portions of the bars. b. The braking distance of Car A is about 40% greater than the braking distance of Car C.
The graph to the right compares teaching salaries of women and men at private colleges and universities. What impression does the graph create? Does the graph depict the data fairly? If not, construct a graph that depicts the data fairly. a.What impression does the graph create? b.Does the graph depict the data fairly?
a. The graph creates the impression that men have salaries that are more than twice the salaries of women. b. No, because the vertical scale does not start at zero.
Use the pulse rates (beats per minute) of males in the accompanying data set to construct a frequency distribution. Begin with a lower class limit of 40 and use a class width of 10. Do the pulse rates of males appear to have a normal distribution? b.) Do the pulse rates of males appear to have a normal distribution?
a.) Pulse Rate Frequency 40-49 2 50-59 21 60-69 55 70-79 41 80-89 27 90-99 5 100-109 2 b.)The pulse rates of males appear to have a normal distribution because the frequencies start low, increase, and then decrease; and are roughly symmetric.
The table below shows the magnitudes of the earthquakes that have occurred in the past 10 years. magnitude Frequency 5.0-5.9 6 6.0-6.9 6 7.0-7.9 13 8.0-8.9 4 9.0-9.9 2 Use the frequency distribution to construct a histogram. Using a loose interpretation of the requirements for a normal distribution, does the histogram appear to depict data that have a normal distribution? Why or why not?
a.) Does the histogram appear to depict data that have a normal distribution? The histogram appears to roughly approximate a normal distribution. The frequencies generally increase to a maximum and then decrease, and the histogram is symmetric.
