Question

Erythropoietin (EPO) is a banned drug used by athletes to increase the oxygen-carrying capacity of their blood. New tests for EPO were first introduced prior to the 2000 Olympic Games held in Sydney, Australia. Chance (Spring 2004) reported that of a sample of 830 world-class athletes, 159 did not compete in the 1999 World Championships (a year prior to the new EPO test). Similarly, 133 of 82:5 potential athletes did not compete in the 2000 Olympic Games. Was the new test effective in deterring an athlete's participation in the 2000 Olympics? If so, then the proportion of nonparticipating athletes in 2000 will be greater than the proportion of nonparticipating athletes in 1999, Use a 98% confidence interval to compare the two proportions and make the proper conclusion.

Answer 1

Step-by-step

The null and the alternative hypothesis can be define as follows,

Null Hypothesis; There is no significance difference between the proportions of non participating athletes in 1999 and 2000

`H_0:(p_1-p_2)\\eq 0`

Alternative Hypothesis: The proportion of non participating athletes in 2000 will be more than the proportion of non participating athletes in 1999

`H_1:(p_1-p_2)<0`

The proportion of nonparticipating athletes in 1999 is given by

`\hat p_1 = (x_1)/(n_1) \\\\=(159)/(830) =0.1916`

The proportion of nonparticipating athletes in 2000 is given by

`\hat p_2 =(x_2)/(n_1) \\\\=(133)/(825) =0.1612`

The pooled proportion can be calculated using the following formula

`\hat p = (x_1+x_2)/(n_1+n_2) \\\\=(159+133)/(830+825) =0.1764`

under the null hypothesis, the test statistics can be calculated as follows

`Z=\frac{\hat p_1 - \hat p_2}{\sqrt{\hat p \hat q((1)/(n_1)+(1)/(n_2) ) } }`

`=\frac{0.1916-0.1612}{\sqrt{(0.1764)(0.8236)((1)/(830) +(1)/(825) )} } \\\\=1.6257`

Determine the P-value using the following formula

P-value = Normdist(1.6257)

=0.947993

Here, it can be observed that the P-value is greater than the level of the significance,

Hence, the null hypothesis fails to be rejected

Therefore it can be concluded that there is insufficient evidence to support that the proportions of non participating athletes in 2000 will be more than the proportions of non participating athletes in 1999