# QRB 501 FINAL EXAM 36 ANWSERS

Topics: Standard deviation, Skewness, Arithmetic mean Pages: 7 (1310 words) Published: November 7, 2013
﻿1) Write the following as an algebraic expression using x as the variable: Twelve less than six times a number   A.  6x – 12 [(Six times a number means 6x, and twelve less mean -12)]  B.  –6x
C.  –12(6x)
D.  12 – 6x
2) Write the following as an algebraic expression using x as the variable: The sum of a number and -8   A.  -8 + x [(let x be the variable number, therefore sum of variable (x) and (-8) would be x-8 or -8 + x)]  B.  -8 - x

C.  x(-8)
D.  -8x
3) Write the following as an algebraic expression using x as the variable: Triple a number subtracted from the number   A.  x - 3x [(let x be the unknown number, and triple that number would be 3x. Triple a number (3x) has to be subtracted from the number, which is x, thus x-3x)]  B.  x 3 – x

C.  3x - x
D.  3(x - x)
4) Solve: (–5)2 · (9 – 17)2 ÷ (–10)2
A.  16 [(-5)^2 . (9-17)^2 ÷ (-10)^2 = (25) . (64) ÷ (100) = 1600 ÷ 100 = 16]  B.  64
C.  -6.4
D.  -.039

5) Solve: 3(-19 + 4) ÷ -5
A.  9 [ 3(-15) ÷ -5 which equals (-45) ÷ (-5) = 45 ÷ 5 = 9]  B.  -13.8
C.  0.11
D.  13.8
6) Solve: –9 + 18 ÷ –3(–6)
A.  27
B.  90
C.  -0.5
D.  0.5 [(-9 + 18) ÷ 18 = 9 ÷ 18 = ½ = 0.5]
7) Identify the variable, constant, and coefficient of the expression: 10k – 15   A.  variable: k; constant: 15; coefficient: 10
B.  variable: 10; constant: k; coefficient: –15
C.  variable: 15; constant: 10; coefficient: k
D.  variable: k; constant: –15; coefficient: 10
8) Identify the variable, constant, and coefficient of the expression: 3p   A.  variable: p; constant: 0; coefficient: 3
B.  variable: 3; constant: 0; coefficient: p
C.  variable: 3; constant: p; coefficient: 3
D.  variable: p; constant: 3; coefficient: 0
9) Identify the variable, constant, and coefficient of the expression: x – y   A.  variable: x and y; constant: 0; coefficient: 1
B.  variable: y; constant: x; coefficient: 0
C.  variable: x; constant: –y; coefficient: 1
D.  variable: x and y; constant: 0; coefficient: 0
10) Solve the system of equations:
3x = 7 – y
2y = 14 – 6x

A.  { (x,y) ¦ 3x + y = 7 } [( 3x = 7 – y )  shifting –y to the left hand side we get 3x + y = 7  B.  { (x,y) ¦ –3x + y = 7 }
C.  { (x,y) ¦ 2x + y = 3 }
D.  { (x,y) ¦ x + y = 2 }

11) Solve the system of equations:
3x + y = –7
x – y = –5
A.  { (–3,2) } 3x + y = –7 Equation -1 and x – y = –5 equation 2 |adding equation 1 and 2 we get 4x = -12 therefore x = -3| When we input x = -3 in equation 1, we get 3(-3) + y = -7| which equals -9 + y = -7, therefore y = -7 + 9 = 2 therefore, x= -3, y = 2. Answer: {(-3,2)}  B.  { (–4,1) }

C.  { (–2,–1) }
D.  { (1,–8) }

12) Solve the system of equations:
4x + 3y = 1
3x + 2y = 2
A.  { (4,–5) } 4x + 3y = 1 Equation 1,
3x + 2y = 2 Equation 2, multiply eq. 1 with 3 and eq. 2 with 4 we get, 12x + 9y = 3 eq. 3 , 12x + 8y = 8 eq. 4
Now subtracting eq. 4 with eq. 3 we get
y = -5, Input y= -5 in eq. 1, we get 4x -15 =1 ,therefore 4x= 16, x =4 answer {(4,-5)}
B.  { (–1,2) }
C.  { (–2,3) }
D.  { (1,–1) }
13) A man earned \$80,000 when the Consumer Price Index was 200. What were his earnings in terms of \$2,000 if the base period was 2000?   A.  \$160,000
B. \$40,000 CPI is defined as (Current value/Base year value) * 100, Here, CPI = 200, Current value = 80000, therefore, 200 = (80000/Base year value) * 100, Base year value = (80000/200) * 100 = 40000  C.  \$60,000

D.  \$80,000
14) Which of the following is true of an index?

A.  It shows a percent change from one period to another  B.  It must be larger than 100
C.  It cannot assume negative values
D.  It can employ qualitative data
15) Which of the following is true of a base period for an index number?   A.  The numerator spears
B.  It cannot be less than 100
C.  It must have occurred after the year 1980
D.  It appears in the denominator
16) What happens as we increase the number of classes in a histogram?   A.  Central tendency becomes more obvious...