SOLUTION: Checkout Time (in minutes) Frequency 1.0 - 1.9 6 2.0 - 2.9 7 3.0 - 3.9 2 4.0 - 4.9 3 5.0 - 5.9 2 4. What percentage of the checkout times was at least 4 minutes? (5 pts) 5.

Algebra ->  Probability-and-statistics -> SOLUTION: Checkout Time (in minutes) Frequency 1.0 - 1.9 6 2.0 - 2.9 7 3.0 - 3.9 2 4.0 - 4.9 3 5.0 - 5.9 2 4. What percentage of the checkout times was at least 4 minutes? (5 pts) 5.       Log On


   

Question 872802: Checkout Time (in minutes) Frequency
1.0 - 1.9 6
2.0 - 2.9 7
3.0 - 3.9 2
4.0 - 4.9 3
5.0 - 5.9 2
4. What percentage of the checkout times was at least 4 minutes? (5 pts)
5. Calculate the mean of this frequency distribution. (5 pts)
6. Calculate the standard deviation of this frequency distribution. (10 pts)
7. Assume that the smallest observation in this dataset is 1.2 minutes. Suppose this observation were incorrectly recorded as 0.12 instead of 1.2. Will the mean increase, decrease, or remain the same? Will the median increase, decrease or remain the same? Explain your answers.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!



Hi

x	n	nx	x -2.85	n(x -2.85)^2	

1.45	6	8.7	-1.4	11.76	

2.45	7	17.15	-0.4	1.12	

3.45	2	6.9	0.6	0.72	

4.45	3	13.35	1.6	7.68	

5.45	2	10.9	2.6	13.52	

					

	20	57		34.8	

	mean	2.85		1.74	Variance

				1.32	SD

4. What percentage of the checkout times was at least 4 minutes? 5/20 = 25%

 5. Calculate the mean of this frequency distribution. 2.85

 6. Calculate the standard deviation of this frequency distribution. 

Variance = 1.74 (34.8/20) n used as divisor

SD = sqrt(1.74) = 1.32