A random sample of size n₁ = 16 is selected from a normal population with a mean of 75and a standard deviation of 8. A second random sample of size n₂ = 9 is taken from anothernormal population with mean 70 and standard deviation 12. Let X₁ and X₂ be the two samplemeans. Find:(a) The probability that X₁ X₂, exceeds 4(b) The probability that 3.5 ≤ X₁ – X₂ ≤ 5.5

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Answered: A random sample of size ₁ = 16 is…

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Use the Suppose in a local Kindergarten through 12th grade (K -12) school district, 42% of the population favor a charter school for grades K through 5. A simple random sample of 144 is surveyed. nd the mean and the standard deviation of X of B(144, 0.42). Round off to 4 decimal places. b. Now approximate X of B(144, 0.42) using the normal approximation with the random variable Y and the table. Round off to 4 decimal places. Y N( C Find the probability that at most 72 favor a charter school using the normal approximation and the table. Round off to z-values up to 2 decimal places.) P(X 68) P(Y > ~ (Z >) e. Find the probability that exactly 63 favor a charter school using the normal approximation and the table. (Round off to z-values up to 2 decimal places.) P(X = 63) P(
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The times to pop a regular bag of microwave popcorn without burning it are Normally distributed with a mean time of 140 seconds and a standard deviation of 20 seconds. The times to pop a mini bag of microwave popcorn, without burning it, are Normally distributed with a mean time of 90 seconds and a standard deviation of 15 seconds. Suppose two independent random samples, 25 of each, are taken and the mean popping times are calculated. Let R = the popping time of a randomly selected regular-sized bag and M = the popping time of a mini-sized bag. Which of the following best describes the mean of the sampling distribution of ? A) –50 B) 50 C) 90 D) 140
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