Homework SourseOnly need questions 13 16 completed question 13 is making r
Only need questions 13 - 16 completed question 13 is making reference to the answer in question 11 so that is why i placed them here as well
| Sample problems related to text\'s Chapter 2 | |||||||||||||||||
| 11. | The number of hours worked by 20 FHSU students over the course of one week is given in the table at the right. Create a reasonable frequency table for this data set with exactly six classes. Include a relative frequency column in the table. | 25 | 15 | 12 | 31 | 35 | |||||||||||
| 0 | 7 | 29 | 16 | 9 | |||||||||||||
| 14 | 30 | 20 | 22 | 38 | |||||||||||||
| 23 | 20 | 15 | 30 | 20 | |||||||||||||
| | |||||||||||||||||
| Data | cumulative | ||||||||||||||||
| lower | upper | midpoint | width | frequency | percent | frequency | percent | ||||||||||
| 0 | < | 7 | 4 | 7 | 1 | 5.0 | 1 | 5.0 | |||||||||
| 7 | < | 14 | 11 | 7 | 3 | 15.0 | 4 | 20.0 | |||||||||
| 14 | < | 21 | 18 | 7 | 7 | 35.0 | 11 | 55.0 | |||||||||
| 21 | < | 28 | 25 | 7 | 3 | 15.0 | 14 | 70.0 | |||||||||
| 28 | < | 35 | 32 | 7 | 4 | 20.0 | 18 | 90.0 | |||||||||
| 35 | < | 42 | 38 | 7 | 2 | 10.0 | 20 | 100.0 | |||||||||
| 20 | 100.0 | ||||||||||||||||
| 12. | Construct an appropriate stem-and-leaf plot for the data given above in #11. Then describe the shape of the distribution of the data set (either skewed left or skewed right or symmetric). (HINT: to keep appropriate spacing, choose Courier font format for cells used to display the plot and begin each entry with an apostrophy to make the values act as text versus a single number. ) | the shape of the distribution of the data set is symmetric | |||||||||||||||
| Frequency | Stem | Leaf | |||||||||||||||
| 3 | 0 | 0 7 9 | |||||||||||||||
| 5 | 1 | 2 4 5 5 6 | |||||||||||||||
| 7 | 2 | 0 0 0 2 3 5 9 | |||||||||||||||
| 5 | 3 | 0 0 1 5 8 | |||||||||||||||
| Sample problems related to text\'s Chapter 3 | 20 | ||||||||||||||||
| 13. | Using the data in #11, determine the following statistics for the data set: | ||||||||||||||||
| a. | mean | ||||||||||||||||
| b. | median | ||||||||||||||||
| c. | mode | ||||||||||||||||
| d. | midrange | ||||||||||||||||
| e. | range | ||||||||||||||||
| f. | standard deviation | ||||||||||||||||
| g. | variance | ||||||||||||||||
| 14. | Give the five-number summary for the data set given in problem #11. Determine if there are any outliers based on the 1.5IQR rule (see page141 in the text). Work must be shown to the right, and final classification of outliers, if any exists, must be stated explicitly. | ||||||||||||||||
| 15. | Answer the two questions below: | ||||||||||||||||
| a. | After first assuming the data represents a population instead of a sample in problem #11, what is the z-score of the last piece of data listed (the data value 20)? | ||||||||||||||||
| b. | Breifly interpret the meaning of this z-score in relation to the data set. | ||||||||||||||||
| 16. | Number of monthly infections reported at a local hospital averaged 129 with a standard deviation of 8.4. During a recent week, the hospital experienced 144 patients with infections. Is that amount considered unsually high if the distribution of number infected tends to be bell-shaped, symmetric? Why or why not? | ||||||||||||||||
Solution
13a. mean=411/20=20.55
b. median =20
c. mode=20
d. midrange=0+38/2=19
e. range=38
f. SD=9.83803
g. variance=SD^2=96.78684
14. min=0
q1=15
med=20
q3=30
max=38
To find outliers:
IQR=30-15=15
IQR*1.5=15*1.5=22.5
q1-22.5=-7.5 so no outliers below
q3+22.5=52.5 so no outliers above
NO OUTLIERS
15a. z=(20-20.55)/9.838=-.0559
b. This Z score means that the data point of 20 is -.0559 standard deviations from the mean.
16. z=(144-129)/8.4=1.79
This corresponds to a p-value of .0367 so we would reject the the null hypothesis in this case that the number of infections aveaged 129, and conclude that the amount of 144 is considered unusally high.
Hope this helps! :) Let me know if you need any more clarifications.
