What is the estimated 95% confidence interval (CI) of the average blood vitamin D level of US landscapers in ng/mL?

Please note the following: 1) you might calculate a CI that is different from any of the multiple choice options listed below due to rounding differences, therefore select the closest match; 2) ensure you use either the large or small sample CI formula as appropriate; and 3) you may copy and paste the data into Excel to facilitate analysis.

Select one:

a. 35.7 to 40.8 ng/mL

b. 36.3 to 41.1 ng/mL

c. 34.0 to 39.2 ng/mL

d. 31.9 to 35.5 ng/mL

Subject

Vitamin D

1

42.755

2

30.488

3

26.986

4

41.431

5

33.993

6

34.521

7

39.203

8

35.367

9

17.324

10

32.894

11

35.598

12

38.944

13

29.151

14

27.079

15

32.771

16

35.945

17

35.879

18

32.026

19

29.204

20

42.383

21

19.197

22

31.161

23

41.189

24

35.168

25

38.581

26

27.437

27

34.140

28

35.310

29

26.147

30

25.373

31

25.629

32

25.715

33

35.936

34

35.151

35

35.966

36

43.051

37

34.368

38

33.032

39

26.809

40

43.662

41

29.920

42

44.856

43

40.338

44

31.873

45

37.412

46

34.877

47

22.106

48

43.985

49

31.579

50

39.498