Question

8. Glass Garbage Generation A survey found that the American family generates an average of 17.2 pounds of glass garbage each year. Assume the standard deviation of the distribution is 2.5 pounds. Find the probability that the mean of a sample of 55 families will be between 17 and 18 pounds. 0.7135 Source: Michael D. Shook and Robert L. Shook, The Book of Odds. 9. College Costs The mean undergraduate cost for tuition, fees, room, and board for four-year institutions was $26,489 for a recent academic year. Suppose

Answer 1

.7147

Explanation:

Let P be the probability of 55 families having mean more than 17

P { (17-17.2)/ (2.5/√55) }

P(- 0.5933 )

= - .2765 [ From the z table ]

P be the probability of 55 families having mean less than 18

P { (18 -17.2)/ (2.5/√55) }

P( 2.3732 )

= .9912 [ From the z table ]

Probability of mean between 17 and 18

= .9912 - .2765

= .7147