Question

5. A machine makes sticks of butter whose average weight is 4.0 ounces; the SD of the weights is 0.05 ounces. There is no trend or pattern in the data. There are 4 sticks to a package. (a) A package weighs , give or take (b) A store buys 100 packages. Estimate the chance that they get 100 pounds of butter, to within 2 ounces. or so. (b) The null says that the percentage of reds in the box is The alternative says that the percentage of reds in the box is Fill in the blanks. (c) Compute z and P. (d) What do you conclude? One large course has 900 students, broken down into section meetings with 30 students each. The section meetings are led by teaching assistants. On the final, the class average is 63, and the SD is 20. However, in one section the average is only 55. The TA argues this way: 9. If you took 30 students at random from the class, there is a pretty good chance they would average below 55 on the final. That's what happened to me-chance variation. Is this a good defense? 10. One kind of plant has only blue flowers and white flowers. According to a genetic model, the offsprings of a certain cross have a 75% chance to be blue-flowering, and a 25% chance to be white-flowering, independently of one another. Two hundred seeds of such a cross are raised, and 142 turns out to be blue-flowering. Are the data consistent with the model?

Answer 1