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 an article, two authors explored the experience and struggles of people diagnosed with dementia and their families. The ages of a simple random sample of

24

people with early-onset dementia have a mean of

52.8

years and a standard deviation of

6.1

years. Complete parts (a) through (c) below.