a-university-claims-the-average-weight-of-textbooks-for-its-engineering-students

Question

A university claims that the average weight of textbooks for its engineering students is 7.57.5 pounds. A random sample of 3636 engineering students' textbook weights is taken, yielding a sample mean of 6.86.8 pounds. If the population standard deviation is known to be 1.81.8 pounds, what is the probability of obtaining a sample mean of 6.86.8 pounds or less?

Accepted Answer

P(xˉ≤6.8)≈0.0099P(\bar{x} \le 6.8) \approx 0.0099

Answer

P(xˉ≤6.8)≈0.3540P(\bar{x} \le 6.8) \approx 0.3540

Answer

P(xˉ≤6.8)≈0.9901P(\bar{x} \le 6.8) \approx 0.9901

Answer

P(xˉ≤6.8)≈0.6460P(\bar{x} \le 6.8) \approx 0.6460