Question

Question 7

1. 7. The following data are the number of burglaries reported for a specific year for nine western Pennsylvania universities. Find the variance.

   61, 11, 1, 3, 2, 30, 18, 3, 7

   	a.	385.36
   	b.	640.36
   	c.	19.63
   	d.	570.89

Question 8

1. 8. Eighty randomly selected light bulbs were tested to determine their lifetimes in hours. This frequency distribution was obtained. Find the standard deviation.

   Class Boundaries	Frequency
   52.5-63.5	10
   63.5-74.5	13
   74.5-85.5	28
   85.5-96.5	15
   96.5-107.5	14

   	a.	188.01
   	b.	13.71
   	c.	6892.69
   	d.	537898.29

  

Question 9

1. 9. What is the term for a normal distribution in which approximately 68% of the data values fall within one standard deviation of the mean?

   	a.	empirical rule
   	b.	right-skewed distribution
   	c.	boxplot
   	d.	differential statistics

Answer 1