# math/probability

posted by
**nascha** on
.

204 / 205 - EXERCISES FOR SECTION 4.2

18- WHAT ARE EQUALY LIKELY OUTCOMES?

19- DESCRIBE THE DIFFERENCE BETWEEN AN IMPOSSIBLE EVENT AND A CERTAIN EVENT IN PROBABILITY. BE SURE TO PROVIDE EXAMPLES.

26- ALZHEIMER'S DISEASE. THE BAR GRAPH IN FIGURE 4.3 SHOWS THE PERCENTAGE OF PEOPLE 65 OR OLDER WHO HAVE BEEB DIAGNOSED WITH PROBALE ALZHEIMER'S DISEASE. FOR EXAMPLE THERE IS A 3% CHANCE THAT A PERSON WHO IS BETWEEN THE AGES OF 65 AND 74 HAS ALZHEIMER'S DISEASE. THUS, THE PROBABILITY IS 3/100 (SEE CHAPTER 12 FOR INFORMATION ON CONVERTING A PERCENT TO A FRACTION):

A. IF WE RANDOMLY SELECT AN 80YEAR OLD PERSON, WHAT IS THE PROBABILITY THAT THIS PERSON WILL HAVE ALZHEIMER'S DISEASE?

B. IF WE RANDOMLY SELECT A PERSON WHO IS AT LEAT 85 YEARS OLD, WHAT IS THE PROBABILITY THAT THIS PERSON DOES NOT HAVE ALZHEIMER'S DISEASE?

C. ARE THE PROBABILITIES SHOWN IN FIGURE 4.3 THEORETICAL OR EMPIRICAL?WHY?

FIGURE 4.3

___________________________________

AGE FACTOR

PERCENTAGE OF PEOPLE 65

AND OLDER WITH PROBABLE

ALZHEIMER'S DISEASE

6-74 -----3%

75-84------- 19%

85-PLUS -------- 47%

SOURCE JOURNAL OF THE AMERICAN

MEDICAL ASSOCIATION

_________________________________