91Ó°ÊÓ

We have drawn a smooth curve that represents a distribution,

a. Identify the shape of the distirbution with regard to modality.

b. Identify the shape of the distribution with regard to symmetry (or non symmetry)

c . If the distribution is unimodal and non symmetric, classify it as either right skewed or left skewed.

We have drawn a smooth curve that represents a distribution,

a. Identify the shape of the distirbution with regard to modality.

b. Identify the shape of the distribution with regard to symmetry (or non symmetry)

c . If the distribution is unimodal and non symmetric, classify it as either right skewed or left skewed.

We have drawn a smooth curve that represents a distribution,

a. Identify the shape of the distirbution with regard to modality.

b. Identify the shape of the distribution with regard to symmetry (or non symmetry)

c . If the distribution is unimodal and non symmetric, classify it as either right skewed or left skewed.

Baltimore Ravens. From Player Roster, the official roster of the 2013 Super Bowl champion Baltimore Ravens, we obtained the heights, in inches, of the players on that team. A dot plot of those heights is as follows.

Cholesterol Levels. According to the National Health and Nutrition Examination Survey, published by the Centers for Disease Control and Prevention, the average cholesterol level for children between 4 and 19 years of age is 165mg /dl. A pediatrician who tested the cholesterol levels of several young patients was alarmed to find that many had levels higher than 200mg / dL. The following relative frequency histogram shows the readings for some patients who had high cholesterol levels.

Sickle Cell Disease. A study published by E. Anionwu et al. in the British Medical Journal (Vol, 282, pp .283-286) measured the steady-state hemoglobin levels of patients with three different types of sickle cell disease. Following is a stem-and-leaf diagram of the data.

Old Faithful. Old Faithful is a geyser in Yellowstone National Park that erupts at relatively predictable intervals. Since 2000, the eruptions of Old Faithfull occur on average every 90 minutes. Information on the daily eruptions of Old Faithful can be found on the website of The Geyser Observation and Study Association (GOSA). The following data provide the times between eruptions, in minutes, for Old Faithful over a two-day period.

a. Use cutpoint grouping with a first class of 60 -under 70 to construct a frequency histogram of the times between eruptions.

b. Identify the shape of the distribution with regard to modality.

c. Identify the shape of the distribution with regard to symmetry (or nonsymmetry).

d. If the distribution is unimodal and nonsymmetric, classify it as either right skewed or left skewed.

Snow Goose Nests. In the article "Trophic Interaction Cycles in Tundra Ecosystems and the Impact of Climate Change" (BioScience, Vol. 55, No, 4, pp, 311-321), R. Ims and E. Fuglei provided an overview of animal species in the northern tundra. One threat to the snow goose in arctic Canada is the lemming. Snowy owls act as protection to the snow goose breeding grounds. For two years that are 3 years apart, the following graphs give relative frequency histograms of the distances, in meters, of snow goose nests to the nearest snowy owl nest.

The Great White Shark. In an article titled "Great White, Deep Trouble" (National Geographic, Vol. 197(4). pp. 2-29). Peter Benchley - the author of JAWS - discussed various aspects of the Great White Shark (Carcharodon Carcharias). Data on the number of pups borne in a lifetime by each of 80 Great White Shark females are given on the WeissStats site.

a. use the technology of your choice to identify the modality and symmetry (or non-symmetry) of the distribution of the data set.

b. if unimodal, classify the distribution as symmetric right-skewed. or left-skewed.

Class Project: Number of Siblings. This exercise is a class project and works best in relatively large classes.

a. Determine the number of siblings for each student in the class.

b. Obtain a relative-frequency histogram for the number of siblings. Use single-value grouping.

c. Obtain a simple random sample of about one-third of the students in the class.

d. Find the number of siblings for each student in the sample.

e. Obtain a relative-frequency histogram for the number of siblings for the sample. Use single-value grouping.

f. Repeat parts (c)-(e) three more times.

g. Compare the histograms for the samples to each other and to that for the entire population. Relate your observations to key Fact 2.1