Dementia is the loss of intellectual and social abilities severe enough to interfere with judgment, behavior, and daily functioning. Alzheimer's disease is the most common type of dementia. In the article "Living with Early Onset Dementia: Exploring the Experience and Developing Evidence-Based Guidelines for Practice" (Alzheimer's Care Quarterly, Vol. 5, Issue 2, pp. 111-122), P. Harris and J. Keady explored the experience and struggles of people diagnosed with dementia and their families. The ages of a simple random sample of 21 people with early-onset dementia have a mean of 52.5 years and a standard deviation of 6.5 years.

a. Construct a graph similar to Fig. 3.8 on page 118.

b. Apply Chebyshev's rule with k = 2 to make pertinent statements about the observations in the sample.

c. Repeat part (b) with k = 3.