Question

please Answer question 9 and 10

Question: Using the computer (Excel), answer the following 10 questions: Assessing Normality Many times in statistics it is necessary to see if a set of data values is approximately normally dis- tributed. There are special techniques that can be used. One technique is to draw a histogram for the data and see if it is approximately bell-shaped. (Note: It does not have to be exactly symmetric to be bell-shaped.) The numbers of branches of the 50 top libraries are shown. 67 84 80 77 97 59 62 37 36 54 18 12 19 33 49 24 24 29 9 21 21 24 31 17 13 19 19 22 22 30 41 22 26 33 14 14 16 22 26 10 Source: The World Almanac and Book of Facts. 33 42 25 22 15 21 18 20 16 24 1. Construct a frequency distribution for the data. 2. Construct a histogram for the data. 3. Describe the shape of the histogram. 4. Based on your answer to question 3, do you feel that the distribution is approximately normal? In addition to the histogram, distributions that are approximately normal have about 68% of the values fall within 1 standard deviation of the mean, about 95% of the data values fall within 2 stan- dard deviations of the mean, and almost 100% of the data values fall within 3 standard deviations of the mean. (See Figure 6-5.) 5. Find the mean and standard deviation for the data. 6. What percent of the data values fall within 1 standard deviation of the mean? 7. What percent of the data values fall within 2 standard deviations of the mean? 8. What percent of the data values fall within 3 standard deviations of the mean? 9. How do your answers to questions 6, 7, and 8 compare to 68, 95, and 100%, respectively? 10. Does your answer help support the conclusion you reached in question 4? Explain.

Question 4 answer is : The distribution is not normally distributed.

Question 6 answer is : 80%

Question 7 answer is : 92%

Question 8 answer is : 98%

Answer 1

9.from the given the Answer from 4,6,7,8,

Here , 80% data values fall 1 standard deviation , 92% values fall 2 standard deviation and 98% of data values 3 standard deviation.

so 68 ,95 and 100% Rule , are not follows .

10. No, the answer does not support the question 4