Question

mean was 0% 85, the median is 86, range from 50 to 95. Describe the level of the test based on the shape of the distribution of scores . In Pall 2018, the STA105 test 2 scores for all section stundkents have the following characteristics The distribution is skewed to the left, the test is an casy test. b. The distribution is skewed to the left, the test is a hard test c. The distribution is skewed to the right, the test is an easy test. d. The distribution is skewed to the right, the test is a hard test e. Can noe be determined with the given information. 6. Which of the following are not affected by outliers? b. mean and quartile a mean and median c. median and standard deviation d. median and quartile 7. Suppose that there are 200 studeats in your school class. What class rank is the 15th percentile? a 15 b.30 215 d. 100 e. cannot be determined 8. Which statement is true about standard deviation? a. It measures the center of the distribution. c. It is not resistant with the outlier b. It can be negative. d. None of them is true. 9. Obtain the five-number summary for the given ordered data. The normal annual precipitation (in inches) is given below for 14 different U.S. cities. 5.1 8.6 120 13.6 18.5 21.3 23.9 27.1 27.8 302 319 33.8 39.1 42.6 a. 5.1, 13.6, 27.1, 31.9, 42.6 b. 5.1, 12.8, 25.5, 32.85, 42.6 c. 5.1, 13.6, 25.5, 31.9, 42.6 d. 5.1, 12.8, 27.1, 32.85, 42.6 10. A data set of the sample consists of five observations, (-1,-1,-1,-1, -1). What is the standard deviation? a. 0 c. -0.2 d.1 e. 0.2

Answer 1

5 ) We are given mean = 76.85 and median = 86 , minimum score = 50 and maximum score = 95

For left skewed distribution the mean is less than median and also median is close to maximum value of the data set.

Therefore test score represents  is left skewed distribution and mean . median values are large enough therefore test would be easy.

So a) is the correct answer.

6) Median and quartiles are not affected by outliers

7) 15th percentile = N*0.15 = 200*0.15 = 30

8) Standard deviation is affected by the outlier

c) it is not resistance with the outlier.

9) Five number summery

c) 5.1 , 13.6 , 25.5 , 31.9, 42.6

10 ) The standard deviation of similar values data set is 0

a) 0