A study was made of 413 children who were hospitalized as a result of motor vehicle crashes. Among 290 children who were not using seat belts, 50 were injured severely. Among children using seat belts, 16 were injured severely (based on data from “Morbidity Among Pediatric Motor Vehicle Crash Victims: The Effectiveness of Seat Belts,’’ by Osberg and Di Scala, American Journal of Public Health, Vol. 82, No. 3).
a) State the null hypothesis and alternative hypothesis.
b) Compute the test statistic.
c) Is there sufficient sample evidence to conclude, at the 0.05 significance level, that the rate of severe injuries is lower for children wearing seat belts?
d) Calculate the p-value.
e) State a conclusion about the null hypothesis and state a final conclusion that addresses the original claim
For any married couple who are members of a squash club, the probability that the husband has a degree is 2/4 and the probability that the wife has a degree is 1/4. The probability that the husband has a degree given that his wife has a degree is 3/9. A married couple is chosen at random.
a) show that the probability of them both having degrees is 3/36
b)Find the probability that only one of them has a degree.
c) Find the probability that neither of them has a degree.
2 answers
A study was made of 413 children who were hospitalized as a result of motor vehicle crashes. Among 290 children who were not using seat belts, 50 were injured severely. Among children using seat belts, 16 were injured severely (based on data from “Morbidity Among Pediatric Motor Vehicle Crash Victims: The Effectiveness of Seat Belts,’’ by Osberg and Di Scala, American Journal of Public Health, Vol. 82, No.
5 answers