STAT 400 Midterm: STAT400 ALL-SECTIONS SPRING2012 0000 MID SOL 1

• School: University of Maryland
• Department: Statistics and Probability
• Course: STAT 400
• Professor: All

Document Summary

Stat 400 exam 2 (4. 3 5. 4) Note: while we"d like to guarantee that this answer key is 100% correct, there may be typos we missed in the proofreading. The current enrollment in calc i is 400 students. Verify that this situation satisfies the rule of thumb for calculating probabilities using a normal approximation. The rule of thumb is that both np and nq must be greater than or equal to 10. Use a normal approximation to a binomial distribution to determine the probability that more than 340 of the current students pass calc i. (don"t forget the correction for continuity. ) P[x > 340] = 1 p[x 340]; for normal approximation use continuity correction 1 p[y < 340. 5] 0052: (12 points) reliability studies use an exponential probability distribution to express the expected life time of a piece of machinery. A production machine in a factory has an expected lifetime of 5 years.