An article described a study of reading speed for undergraduate and graduate students. in a sample of 12 undergraduates, the mean time to read a certain passage was 4.8 seconds, with a standard deviation of 1.9 seconds. in a sample of 24 ph. d. students, the mean time was 2.8 seconds, with a standard deviation of 1.0 seconds. let μxμx represent the population mean for undergraduates and let μyμy represent the population mean for ph. d. students. find a 95% confidence interval for the difference μx−μyμx−μy. round down the degrees of freedom to the nearest integer and round the answers to three decimal places.

Exclude leap years from the following calculations. (a) compute the probability that a randomly selected person does not have a birthday on october 4. (type an integer or a decimal rounded to three decimal places as needed.) (b) compute the probability that a randomly selected person does not have a birthday on the 1st day of a month. (type an integer or a decimal rounded to three decimal places as needed.) (c) compute the probability that a randomly selected person does not have a birthday on the 30th day of a month. (type an integer or a decimal rounded to three decimal places as needed.) (d) compute the probability that a randomly selected person was not born in january. (type an integer or a decimal rounded to three decimal places as needed.)