Question

Two professors at a local college developed a new teaching curriculum designed to increase students' grades in math classes. In a typical developmental math course, 55% of the students complete the course with a letter grade of A, B, or C. In the experimental course, of the 16 students enrolled, 12 completed the course with a letter grade of A, B, or C. Is the experimental course effective at the a=0.01 level of significance? Complete parts (a) through (g). (a) State the appropriate null and alternative hypotheses. Ho: P = 55 versus Hy: P > .55 (Type integers or decimals. Do not round.) (b) Verify that the normal model may not be used to estimate the P-value. Because npo (1-Po) = 4.0' < 10, the normal model may not be used to approximate the P-value. (Round to one decimal place as needed.) (c) Explain why this is a binomial experiment. The trials are independent and the probability of success fixed at .55 for each trial. There is a fixed number of trials with two mutually exclusive outcomes. (Type an integer or a decimal. Do not round.) (d) Determine the P-value using the binomial probability distribution. State your conclusion to the hypothesis test. First determine the P-value. P-value = (Round to three decimal places as needed.)

Answer 1

b)  np(1-p) =    16*0.55*(1-0.55)=       3.96 ≈ 4.0

d) p value =P(X>12) =1-BINOMDIST(12,16,0.55,TRUE) =  0.028