- Find the mean of the following set of numbers. Justify your answer. 12, 16, 19, 22, 28, 30
Answer: mean = (12+16+19+22+28+30)/6=127/6= 21.167 (approx)
2. The following scores were recorded on a 100-point examination: 91, 85, 76, 86, 96, 51, 68, 92, 85, 72, 66, 88, 93, 82, 84 Justify your answer.
(a) Find the mean final examination score.
Answer: 81
(b) Find the median final examination score.
Answer: 85
(c) Is the mean or median a more useful representative of the final examination scores?
Answer:Since the mean utilizes every number in the set, the mean is the most reliable at representing the average of the data.
- Find the mode of the following set of numbers. Justify your answer. 15, 14, 22, 21, 5, 19, 10
Answer: none
- Use the information in the table to create a pictograph. Car Sales Year Car Sales
1997 7,453
1998 8,336
1999 7,678
2000 10,653
2001 9,451
2002 8,654
2003 9,201
6. Find the median of the following set of numbers. 24, 26, 31, 33, 35, 36
Answer: median = (31+33)/2=32
7. The table below gives the number of different types of households according to the 2000 census.
Household type Number
Married couple, family household 54,493,232
Female householder, no husband present 12,900,103
Male householder, no wife present 4,394,012
One person, non-family household 27,230,075
Two or more people, non-family household 6,462,697
Create pie chart for the information.
8. Find the first and third quartiles, Q1 and Q3, of the following set of numbers. Justify your answer. 13, 7, 15, 13, 13, 12, 9, 11, 19, 9
Ordered data is: 7,9,9,11,12,13,13,13,15,19
Answer: Q1=9; Q3=13
11. A. Place the following set of numbers in ascending order. ?2, 8, 0, 2, ? 3, ? 20, 11 B. Place the following set of numbers in ascending order.
Answer: missing info
13. A. Evaluate Justify your answer. B. Add Simplify your answer.
14. A. Add 11 + (-4) = 11-4 = 7
Answer: 7
B. Add Simplify your answer.
- 3/5 + (8/35) = -21/35+8/35=-13/35
Answer: -13/35
15. A. Find the reciprocal of (-1/5)15
(-1/5)15=-3
Answer: -1/3
B. Multiply (–5)(1)(8).
Answer: -40
16.
A. Divide 9/-3
Answer: -3
B. Divide -18/-9
Answer: 2
. 18 A. Subtract -35 - 96.
Answer: -131
B. Add 281 + (-672).
Answer: -391
19. Find the five-number summary of the following set of numbers. Show your work. 341, 233, 181, 368, 247, 551, 286, 223, 313
Ordered data: 181,223,233,247,286,313,368,551
Minimum = 181
Q1=(223+233)/2=228
Q2=(247+286)/2=266.5
Q3=(313+368)/2=340.5
Maximum=551
22. The following information shows a relationship between the speed of a certain car over a 100-mi test trip and the gas mileage obtained: Speed 40 45 50 55 60 Gas mileage 35 33 28 25 22 Use this information to predict the gas mileage associated with a speed of 65 mi/h. Justify your answer.
Speed Gas mileage
40 35
45 33
50 28
55 25
60 22
Regression line: y = -068x+62.5
Correlation is strong and negative since R2=0.9863
If x=65 then y=-0.68(65)+62.5=18.3
Predicted valu for the gas mileage associated with a speed of 65 mi/h is 18.3