Tom keeps all of his favorite marbles in a special leather bag. right know five red marbles four marbles and three marbles are in the bag .
part a: if he randomly chooses one marbles to give to a friend what is the probability that it is blue.

part b: tom does not really want to give away blue marbles and would like to change the probability that he choose a blue marble to 1/10. how many marbles that are not blue could he add to the bag so that the probability of choosing a blue marble becomes 1/10

The survey of study habits and attitudes (ssha) is a psychological test that measures the motivation, attitude toward school, and study habits of students, scores range from 0 to 200. the mean score for u.s. college students is about 115, and the standard deviation is about 30. a teacher who suspects that older students have better attitudes toward school gives the ssha to 55 students who are at least 30 years of age. the mean score is 113.2. assume the population standard deviation is 30 for older students what is the margin of error for a 95% confidence interval for the population mean score for a. older students? b. compute the 95% confidence interval for the population mean score for older students. c. compute the 99% confidence interval for the population mean score for older students. d. compute the 88% confidence interval for the population mean score for older students.