**** Given the following observations: answer questions from 9-10: 408 401 410 415 390 400 395 450 406 Q.9 the sample variance is : a) 360 Q.10 the standard deviation is: b) 414 e) 550 d) Your answer a) 14.7 Q.II the density for X, the lead concentration in gasoline in grams per liter is given by: F(x)-12.5X-1.25 b) 5.44 c) 2.34 d) Your answer 0.1s x s0.5 the mean or expected value of x is equal to: a) 0.147 b) 0.544 c) 0.367 d) Your answer

b.

3) For population standard deviation = 3 and a population mean = 10, find the z scores for the following x: A) x = 11 B) x = 8 C) x = 19 D) x = 2

2.137 Consider the following horizontal box plot: NW 0 2 4 6 8 10 12 14 16 2352 a. What is the median of the data set (approximately)? b. What are the upper and lower quartiles of the data set (approximately)? c. What is the interquartile range of the data set (approximately)? d. Is the data set skewed to the left, skewed to the right, or symmetric? e. What percentage of the measurements in the data set lie to the right of the median? To the left of the upper tebi quartile? f. Identify any outliers in the data.