In: Statistics and Probability
Since an instant replay system for tennis was introduced at a major tournament, men challenged 1426 referee calls, with the result that 421 of the calls were overturned. Women challenged 752 referee calls, and 228 of the calls were overturned. Use a 0.05 significance level to test the claim that men and women have equal success in challenging calls. Complete parts (a) through (c) below.
a. Test the claim using a hypothesis test.
Identify the test statistic.
Identify the P-value.
What is the conclusion based on the hypothesis test?
The P-value is ▼less than/greater than the significance level of α=0.05so▼reject/fail to reject the null hypothesis. There▼is not sufficient/is sufficient evidence to warrant rejection of the claim that women and men have equal success in challenging calls.
b. Test the claim by constructing an appropriate confidence interval.
The 95% confidence interval is
What is the conclusion based on the confidence interval?
Because the confidence interval limits▼include/do not include 0, there ▼does/does not appear to be a significant difference between the two proportions. There ▼is not sufficient/is sufficient evidence to warrant rejection of the claim that men and women have equal success in challenging calls.
c. Based on the results, does it appear that men and women may have equal success in challenging calls?
p1cap = X1/N1 = 421/1426 = 0.2952
p1cap = X2/N2 = 228/752 = 0.3032
pcap = (X1 + X2)/(N1 + N2) = (421+228)/(1426+752) = 0.298
Below are the null and alternative Hypothesis,
Null Hypothesis, H0: p1 = p2
Alternate Hypothesis, Ha: p1 ≠ p2
Test statistic
z = (p1cap - p2cap)/sqrt(pcap * (1-pcap) * (1/N1 + 1/N2))
z = (0.2952-0.3032)/sqrt(0.298*(1-0.298)*(1/1426 + 1/752))
z = -0.39
P-value Approach
P-value = 0.6965
As P-value >= 0.05, fail to reject null hypothesis.
b)
Here, , n1 = 1426 , n2 = 752
p1cap = 0.2952 , p2cap = 0.3032
Standard Error, sigma(p1cap - p2cap),
SE = sqrt(p1cap * (1-p1cap)/n1 + p2cap * (1-p2cap)/n2)
SE = sqrt(0.2952 * (1-0.2952)/1426 + 0.3032*(1-0.3032)/752)
SE = 0.0207
For 0.95 CI, z-value = 1.96
Confidence Interval,
CI = (p1cap - p2cap - z*SE, p1cap - p2cap + z*SE)
CI = (0.2952 - 0.3032 - 1.96*0.0207, 0.2952 - 0.3032 +
1.96*0.0207)
CI = (-0.0486 , 0.0326)
Because the confidence interval limits include 0, there does not appear to be a significant difference between the two proportions. There is not sufficient evidence to warrant rejection of the claim that men and women have equal success in challenging calls.
c)
Yes