In: Statistics and Probability
In a particular year, 68% of online courses taught at a system
of community colleges were taught by full-time faculty. To test if
68% also represents a particular state's percent for full-time
faculty teaching the online classes, a particular community college
from that state was randomly selected for comparison. In that same
year, 31 of the 44 online courses at this particular community
college were taught by full-time faculty. Conduct a hypothesis test
at the 5% level to determine if 68% represents the state in
question.
Note: If you are using a Student's t-distribution for the
problem, you may assume that the underlying population is normally
distributed. (In general, you must first prove that assumption,
though.)
A. State the distribution to use for the test. (Round your
standard deviation to four decimal places.)
P' ~ ________ (________,_________)
B. What is the test statistic? (Round your answer to two decimal places.)
C. What is the p-value? (Round your answer to four decimal places.)
D. Indicate the correct decision ("reject" or "do not reject" the null hypothesis), the reason for it, and write an appropriate conclusion.
(i) Alpha:
α =
E. Construct a 95% confidence interval for the true proportion. Sketch the graph of the situation. Label the point estimate and the lower and upper bounds of the confidence interval. (Round your answers to four decimal places.)
Given : n=44 , X=31 , The sample proportion , p=X/n=31/44=0.7056
Hypothesis : Vs
A) We use the normal distribution.
Where , and
B) The test statistic is ,
C) p-value=
; From standard normal distribution table
D) Decision : Here , p-value=0.7188 >
Therefore , do not reject Ho
Conclusion : Hence , there is sufficient evidence to support the claim that the 68% also represents a particular state's percent for full-time faculty teaching the online classes.
F) The 95% confidence interval for the true proportion is ,
Where , ; From standard normal distribution table