Answer #4 a,b,c 3. You conducted a survey to learn more about the student body o
ID: 3062122 • Letter: A
Question
Answer #4 a,b,c 3. You conducted a survey to learn more about the student body of CCD. You asked 500 students whether they have a family (spouse and children) and how many credits they are taking. Number of credit taking Do you have a family Yes No Totals 12 18 Totals 125 74 199 68 113 181 24 96 120 217 283 500 a. What is the probability that a student is without a family and taking 12 credits? b. What is the probability that a student has a family and taking 12 or more credits? c. Given that the student has a family, what is the chance of he/she will take 18 credits? d. Given that the student is taking 12 credits, what is the chance he/she doesn't have a family? 4. Scores on a certain test are normally distributed with a mean of 77.5 and a standard deviation of 9.3. a. What is the probability that an individual student will score more than 90? b, what scores represent the cutoff for the middle 95%? c. What proportion of the population will have a score between of 70 and 857Explanation / Answer
Q 3 a) Prob( without family and 12 credit) = 113/500 =0.226
b) Prob( With credit and 12 oe more credit) = (68+24)/500 =92/500 =0.184
c) P(18 credit|have family) = P(18 credit with family)/ P(family) = 24/217 =0.111
d) P(does not have family| 12 credit) =P(12 credit without family)/ P(12 credit) = 113/181 = 0.624