Assignment:
Last Digits of Weights Data Set in Appendix includes weights from 40 randomly selected adult males and 40 randomly selected adult females. Those weights were obtained as part of the National Health Examination Survey. When obtaining weights of subjects, it is extremely important to actually weigh individuals instead of asking them to report their weights. By analyzing the last digits of weights, researchers can verify that weights were obtained through actual measurements instead of being reported. When people report weights, they typically round to a whole number, so reported weights tend to have many last digits consisting of 0.
In contrast, if people are actually weighed with a scale having precision to the nearest 0.1 pound, the weights tend to have last digits that are uniformly distributed, with 0, 1, 2,......, 9 all occurring with roughly the same frequencies.
Table shows the frequency distribution of the last digits from the 80 weights listed in Data Set in Appendix. (For example, the weight of 201.5 lb has a last digit of 5, and this is one of the data values included in Table.) Test the claim that the sample is from a population of weights in which the last digits do not occur with the same frequency. Based on the results, what can we conclude about the procedure used to obtain the weights?
Table Last Digits of Weights
|
Last Digit
|
Frequency
|
|
0
|
7
|
|
1
|
14
|
|
2
|
6
|
|
3
|
10
|
|
4
|
8
|
|
5
|
4
|
|
6
|
5
|
|
7
|
6
|
|
8
|
12
|
|
9
|
8
|