In: Statistics and Probability
For one binomial experiment,
n1 = 75
binomial trials produced
r1 = 30
successes. For a second independent binomial experiment,
n2 = 100
binomial trials produced
r2 = 50
successes. At the 5% level of significance, test the claim that the probabilities of success for the two binomial experiments differ.
(a) Compute the pooled probability of success for the two
experiments. (Round your answer to three decimal places.)
0.457
(b) Check Requirements: What distribution does the sample test
statistic follow? Explain.
The Student's t. The number of trials is sufficiently large.The standard normal. The number of trials is sufficiently large. The standard normal. We assume the population distributions are approximately normal.The Student's t. We assume the population distributions are approximately normal.
(c) State the hypotheses.
H0: p1 < p2; H1: p1 = p2H0: p1 = p2; H1: p1 ≠ p2 H0: p1 = p2; H1: p1 < p2H0: p1 = p2; H1: p1 > p2
(d) Compute p̂1 - p̂2.
p̂1 - p̂2 =
Compute the corresponding sample distribution value. (Test the
difference p1 − p2. Do not
use rounded values. Round your final answer to two decimal
places.)
(e) Find the P-value of the sample test statistic. (Round
your answer to four decimal places.)
(f) Conclude the test.
At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant.At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant. At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant.At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.
(g) Interpret the results.
Reject the null hypothesis, there is insufficient evidence that the proportion of the probabilities of success for the two binomial experiments differ.Fail to reject the null hypothesis, there is insufficient evidence that the probabilities of success for the two binomial experiments differ. Reject the null hypothesis, there is sufficient evidence that the proportion of the probabilities of success for the two binomial experiments differ.Fail to reject the null hypothesis, there is sufficient evidence that the proportion of the probabilities of success for the two binomial experiments differ.
HYPOTHESIS TEST
We have to perform two sample proportion test.
We have to test for null hypothesis
against the alternative hypothesis
Our test statistics is given by
Here,
First sample size
Second sample size
First sample proportion
Second sample proportion
[Using R-code '1-pnorm(1.314144)+pnorm(-1.314144)']
Level of significance
We reject our null hypothesis if
Here, we observe that
So, we cannot reject our null hypothesis.
ANSWER
(a)
The pooled probability of success for the two experiments is
(b)
The sample test statistic follows the standard normal. We assume the population distributions are approximately normal.
(c)
and
(d)
Corresponding sample distribution value is
(e)
(f)
At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant.
(g)
Fail to reject the null hypothesis, there is insufficient evidence that the probabilities of success for the two binomial experiments differ.