Work sheet #7 STA 2023

a) Find the z-score for each. (Make sure you write “z = “ ) Round to 2 decimal places.

b) Tell if it’s unusual or not unusual

.

If you can use a calculator screen, then you should. Only use a formula if it’s necessary!!

Women’s weights are normally distributed with a mean of 143 lb. and s = 29 lb.

1) One woman’s weight is 155

2) A sample of 36 women has a mean weight of 155.

3) One woman has a weight of 125.

4) A sample of 100 woman has a mean weight of 125.

5) 56 women have a mean weight of 147.

6) A sample of 240 women has a mean weight of 147.

7) m = 2.0 for GPA’s and s = .8 .One student has a GPA of 2.2.

8) m = 2.0 for GPA’s and s = .8 and a sample of 49 students has a mean GPA of 2.2.

9) m = 2.0 for GPA’s and s = .8 and a sample of 120 students has a mean GPA of 2.2.

10) Mean body temperature is thought to be 98.6. A sample of 35 patients had a mean of 98.24 and s = 0.56.

11) p = .2, n = 880 and x = 149

12) 454 out of 850 drivers change tapes or CD’s while driving and p = .5 from a survey last year.

13) Out of 611 voters, 308 said they voted for the candidate who won and p = .43 from a previous election.

14) 20 items out of 1234 scanned were overcharges with p = 1% when there is not a sale.

15) 144 out of 785 randomly selected subjects who completed college smoke. The rate for the general population is 27%.