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Use the following scenario for problem 14 through 25. How confident are you that

ID: 2956220 • Letter: U

Question

Use the following scenario for problem 14 through 25. How confident are you that the office of Homeland Security is taking the necessary actions to keep you safe from terrorist attacks in the coming year? Confidence is measured in accordance with the scale below.

0=0%, 1=10%, 2=20%, 3=30%, 4=40%, 5=50%, 6=60%, 7=70%, 8=80%, 9=90%, 10=100%

I asked 11 people in New York City this question this past week. Here is an enumeration of their results.

10 7 9 10 6 8 10 10 7 1 10

14. What is the variable in this scenario? ________________

15. This variable is measured at which level of measurement? _______________

16. Construct the frequency and percentage summary tables.

17. For these data what is the mode? ___________

18. For these data what is the mean? ___________

19. Interpret the mean.

20. For these data what is the median? ___________

21. For these data calculate the 11 deviations.

22. For these data calculate the 11 squared deviations.

23. For these data calculate the variance. ___________

24. For these data calculate the standard deviation. __________

25. Are these data symmetric or skewed? Which statistics from those above did you use to answer this question? If skewed, is the skew right or left?


Explanation / Answer

14) terrorist attacks -------------------------------------------------- 15) Ratio level -------------------------------------------------- 16) x frequency Percentage 1 1 0.090909091 6 1 0.090909091 7 2 0.181818182 8 1 0.090909091 9 1 0.090909091 10 5 0.454545455 -------------------------------------------------- 17) Mode =10 -------------------------------------------------- 18) Mean = 6.833333 -------------------------------------------------- 19) Mean number of attacks is 6.833333 -------------------------------------------------- 20) Median=7.5 ------------------------------------------------- 21) x Deviations 1 -5.833 6 -0.833 7 0.167 8 1.167 9 2.167 10 3.167 ------------------------------------------------------ 22) x Deviations Squared deviations 1 -5.833 34.023889 6 -0.833 0.693889 7 0.167 0.027889 8 1.167 1.361889 9 2.167 4.695889 10 3.167 10.029889 -------------------------------------------------- 23) Sample variance =10.16666667 -------------------------------------------------- 24) Sample standard deviation=3.188521078 ------------------------------------------------------- 25) The data is skewed. because the mean is less than median, the data is said to be skewed to the left.