the probability of an event occurring is the complement. the probability of the event and its complement have a sum of___.

14. (05.02 lc) what is the value of y in the solution to the following system of equations? (5 points) 2x + y = −4 5x + 3y = −6

Walgreens sells both kleenex and nyquil. in a random sample of 5000 purchases, it was found that 1200 contained kleenex and 540 contained nyquil. these are not independent because sick people are more likely to buy both and healthy people more likely to buy neither. in looking into that, it was found that 360 purchases contained both. a. make a two-way table to display this information. fill in the table with the missing entries, and be sure your table has row and column totals. b. if we randomly select a purchase that contained kleenex, what is the probability it also contained nyquil? c. what percent of all purchases didn’t contain either product?

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.