Ww2.justanswer.com



1.

A poll of registered voters in Florida asking which candidate they support: NOMINAL

The length of time required for a wound to heal when using a new medicine: RATIO

The number of telephone calls arriving at a switchboard per five-minute period: RATIO

The distance first-year college football players can kick a ball: RATIO

Mental health diagnoses present in an elderly population: NOMINAL

The rankings of employees on their job performance: ORDINAL

2. (5 * 2)/200 = 10/200 = 5%

3.

z = (x - mu)/sigma

z = (45 - 38)/3

z = 7/3

z = 2.33

Using Excel NORMSDIST, p = 0.9902

That means that 99% of students will be able to complete the work in the time she has left.

4.

variance

a) Mean = (7 + -12 + 4 + -7 + 3 + -10) / 6 = -2.5

b) Median = average of two middle datapoints = (-7 + 3)/2 = -2

c) Mode: none

d)

s = sqrt [ Σ (x - xbar)^2 / (n-1)]

s = sqrt[( (7--2.5)^2 + (-12--2.5)^2 + (4--2.5)^2 + (-7--2.5)^2 + (3

--2.5)^2 + (-10--2.5)^2 )/5]

s = sqrt[( 9.5^2 + -9.5^2 + 6.5^2 + -4.5^2 + 5.5^2 + -7.5^2 )/5]

s = sqrt[( 90.25 + 90.25 + 42.25 + 20.25 + 30.25 + 56.25) /5]

s = sqrt (329.5/5)

s = sqrt (65.9)

s = 8.1179

e) Range = max - min = 7 - -12 = 19

f) Variance: from calculations in d) above, s^2 = 65.9

5.

Chemistry:

z = (x - mu)/sigma

z = (81 - 70)/20

z = 11/20

z = 0.55

Using Excel NORMSDIST, p = 0.7088

History:

z = (x - mu)/sigma

z = (75 - 65)/8

z = 10/8

z = 1.25

Using Excel NORMSDIST, p = 0.8944

The student did better in history. She scored 1.25 SD above the mean, which is better than 89% of the students. In Chemistry, the student scored 0.55 SD above the mean, which is better than 71% of the

students.

6. Convenience sampling. It doesn't give a random sample, so it's not possible to make inferences about the results in the population as a whole. The students you ask likely don't include some important subgroups.

7. Nominal variables

8. A testable hypothesis

9. The null hypothesis

10. 7.8

11. 8

12. 7

13. 5

14. 2.56

15. The curve extends to + and – 3 standard deviations from the mean

16. 68

17. Degrees of freedom

18. Rejecting the null hypothesis when in reality the null hypothesis is true

19. convenience sampling

20. number of subjects

21. all of the above are true

22. Boys who play sports are not viewed as more attractive than boys who do not play sports

23. Rejected at the .05 level

24. 20

25. If each participant is measured twice

26.

In my opinion, none of these answers is correct.

95% falls within 2 sd of the mean

68% falls within 1 sd of the mean.

95% - 68% = 27%, which is the correct answer.

It’s possible that the question means, “within either 1 or 2 sd of the mean”. The answer to that would be 95%.

27. Mean

28. Frequencies

29. Standard deviation

30. 68% of 300 = 204

31. Mean

32. z scores

33. Range

34. Mode

35. 0.45 + 0.35 – 0.25 = 0.55

36. The new mean distance is less than 8.2 miles.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download