Question

The investigator was concerned that the results might be confounded by age. She stratified the results, displaying them separately for the older subjects (aged 65 and over) and the younger subjects (aged 40-64). Examine the two tables below Results among older subjects: CHD Yes No Total Bald Hairy 100 900 Total8507,650 8,500 750 6,750 7,500 1,000 Results among younger subjects: CHD Total 2,500 9,000 Yes No Bald 25 2,475 Hairy 90 8,910 Total 115 11,385 11,500

a. What proportion of the older men are bald?

b. What proportion of the younger men are bald?

c. Does there appear to be an association between age and baldness?

Answer 1

(1.) The proportion of bald older men can be calculated as :-

Total population of men are =7500

No. Of Bald men are= 750

% of bald men are = (750÷7500)×100= 0.1× 100= 10 % of older men are bald.

(2.) The proportion of total no. Of younger subject can be calculated as:-

Total no of younger subject observed are = 2500.

Total no. Of bald younger men are = 25.

Proportion of bald younger men is = (25÷2500)×100= 0.01× 100= 1 % of younger objects are bald.

(3.) effects of age on male pattern baldness:-

Baldness among male is very common it grows with age because of changing hormone levels with age. Male baldness is also known as androgenetic alopecia . Male baldness psychologically may distress men. There are three main causes of hair loss among men :- male baldness may occur because of genetics, age and hormonal change. Nutritional deficiencies, infections, and some psychological conditions may also responsible for hair loss among men.

Genetic factors are also cause male-pattern baldness. Because of genetics factors there is a gradual shrinkage of the tiny cavities in the skin at the base of hairs, known as scalp hair follicles. Hair growth stop progressing and grow shorter as compared to new hairs growth which cause more hair loss.

As above report statistics result conclude that male pattern baldness is more in older subjects (aged over 65 years ) as compared to the younger subjects.