In: Statistics and Probability
A college entrance exam company determined that a score of 22 on the mathematics portion of the exam suggests that a student is ready for college-level mathematics. To achieve this goal, the company recommends that students take a core curriculum of math courses in high school. Suppose a random sample of 250 students who completed this core set of courses results in a mean math score of 22.5 on the college entrance exam with a standard deviation of 3.9.
Verify that the requirements to perform the test using the t-distribution are satisfied. Check all that apply.
A. The students' test scores were independent of one another.
B. The sample size is larger than 30.
C. The students were randomly sampled.
D. None of the requirements are satisfied.
(a)
It is verified that the requirements to perform the test using the t-distribution are satisfied.
A. The students' test scores were independent of one another.
C. The students were randomly sampled.
(b)
H0: Null Hypothesis: 22
HA: Alternative Hypothesis: 22
SE = s/
= 3.9/
= 0.2467
Test Statistic is given by:
t = (22.5 - 22)/0.2467
= 2.0271
Take = 0.05
ndf = 250 - 1 = 249
From Table, critical value of t = 1.6510
Since calculated value of t is greater than critical value of t, the difference is significant. Reject null hypothesis.
Conclusion:
The data support the claim that students are ready for college-level mathematics by achieving the goal of a score of 22 on the mathematics portion of the exam.