4/3/2016 USATestprep, Inc. http://www.usatestprep.com/modules/quiz_factory/qf.php?testid=535 1/18 Coordinate Algebra EOC (GSE) Quiz Answer Key Interpreting Categorical and Quantitative Data - (MGSE9‐12.S.ID.6c ) Fit Linear Function Student Name: _______________________ Date: _________ Teacher Name: THUYNGA DAO Score: _________ 1) Which of the choices is NOT a good example of a line of best fit? A) B) C) D) Explanation: The solution is B. The line in choice B does not correspond with the scatterplot.
3) Which of the choices is the best example of a line of best fit for the scatterplot?
A)
B)
C)
D)
Explanation:The solution is D. The line in choice D best matches the scatterplot.
4) Matt considers whether or not the amount of time students study for a test and the grade on the test are related. He determinesthat the more they study the higher grade they will get. What type of slope would the line of best fit have?
A) negative
B) positive
C) undefined
D) zero
Explanation:positive slope is the correct answer. As the value on the x-axis increases so does the value on the y-axis therefore causing a positiveslope.
10) Jill has a data set that relates amount of snowfall (in inches) to number of traffic accidents. The line of best fit for the data has alarge positive slope, meaning that the more snowfall, the more traffic accidents that occur.
Which would be the MOST LIKELY scatterplot for this data set?
Explanation:Since the line of best fit has a large positive slope the graph needs be increasing. As you move further out to the right on the x-axis,the y-values need to be increasing. Since the description did say large, you want to choose the graph with the sharper increase,which is graph A.
11)
Which equation BEST represents the line of best fit for the scatterplot?
A) y = x + 2
B) y = x + 1
C) y = x - 2
D) y = 2x + 1
Explanation:The solution is A. The scatterplot is best represented by a line with a y-intercept of 2 and a slope of 1.
12)
Which equation BEST represents the line of best fit for the scatterplot?
A) y = 2x
B) y = 2x + 2
C) y = -2x + 2
D) y = x + 2
Explanation:The solution is y = 2x + 2. The line of best fit has a y-intercept of 2 and a slope of 2.
Explanation:Enter the points onto a graphing calculator. If you are using a TI-83 use the STAT button to edit the data into a table and the STAT-CALC option to find the LinReg(ax+b). The equation y = 3x + 2 is the line of best fit for this data.
14)
Which equation BEST represents the line of best fit for the scatterplot?
A) y = 3x
B) y = x - 2
C) y = x - 3
D) y = x + 3
Explanation:The solution is y = x - 3. The scatterplot is best represented by a line with a y-intercept of -3 and slope of 1.
Which linear equation BEST represents the line of best fit for the scatterplot?
A) y = x
B) y = 3x
C) y = -3x
D) y = 5x + 1
Explanation:The solution is y = 3x. The y-intercept is 0 and the slope is approximately 3. Therefore, the line of best fit is y = 3x.
16)
Which linear equation is the BEST representation of the line of best fit for the scatterplot?
A) y = 3
B) x = 3
C) y = -3
D) x = -3
Explanation:The solution is x = -3. Since the line is vertical we can conclude that the equation is x = #. Since the line crosses the x-axis at -3, weknow that the equation is x = -3.
17)
Which linear equation BEST represents the line of best fit for the scatterplot?
Which equation is the BEST fit for the data in the graph?
A) y = 8x – 75
B) y = 75x – 8
C) y = -8x + 75
D) y = -75x + 8
Explanation:By first sketching a line of best fit then comparing it to the given equations, the equation that best matches the graph is y = -8x + 75.
20)
Which equation best represents the line of best fit for the scatterplot?
A) y = x + 6
B) y = 2x + 6
C) y = -x + 6
D) y = -2x + 6
Explanation:The solution is y = -x + 6. The line of best fit for the scatterplot has a y-intercept of 6 and a slope of -1. This results in the equation y= -x + 6.
21) What is the line of best fit for these points?
Explanation:On a TI-83 enter points in the STAT list mode. Then use the STAT-CALC funtion to determine the linereg(ax+b). The line of best fitfor this data is y = 2x + 6.
22)
Which equation is the BEST fit for the data in the graph?
A) y = x + 3
B) y = 9
8x + 4
C) y = 8
9x + 4
D) y = x + 4
Explanation:By first sketching a line of best fit then comparing it to the given equations, the equation that best matches the graph is y = x + 3.
The graph shows Jessica's weight as it compares to her age.
Using the line of best fit what is the best approximation for Jessica's weight at age 10?
A) 60 pounds
B) 70 pounds
C) 80 pounds
D) 90 pounds
Explanation:The solution is 80 pounds. At age 8 she weighs approximately 70 pounds, so if the pattern continues, she will weigh about 80pounds at age 10.
24)
Which equation BEST represents the line of best fit for the scatterplot?
A) y = x
B) y = -x
C) y = x + 1
D) y = x - 1
Explanation:The solution is y = x. The scatterplot is best represented by a line with a y-intercept of 0 and a slope of 1.
Managers at a company rate employees according to job performance and attitude. The results for several randomly selectedemployees are given in the table. Find the equation of the regression line. [Let x = performance and y = attitude. Round the finalvalues to three significant digits, if necessary.]
A) y = 11.7 + 1.02x
B) y = 2.81 + 1.35x
C) y = 11.7 + 2.02x
D) y = -47.3 + 2.02x
Explanation:y = 11.7 + 1.02x is correct, and can be found using the least-squares method or a calculator.
26)
The graph shows number of car horns heard on a busy street since midnight. If the trend continues, how many horns should youhear at 6 pm?
A) 2
B) 30
C) 38
D) 45
Explanation:If you had a line to model the data the slope is approximately 2 meaning that for every hour that passes 2 more horns are heard. Aline to model this data could be y = 2x + 2. If you plug in 18 (6 pm is 18 hours after midnight) you could predict that you would hear38 car horns.
What is the equation for the line of best fit for this set of data?
A) y = -2x
B) y = -2x + 2
C) y = -2x + 2a + b
D) y = -2x + 2a - b
Explanation:y = -2x + 2a + b is correct. Since there are only two points given, the line of best fit is the line determined by the points. The slope is
m = ((b - 4) - b)
((a + 2) - a) = -2. Using this and point (a, b) yields the point-slope equation y - b = -2(x - a), which reduces to y = -2x + 2a + b.
28)
Karl Roberts, CEO of Arko Equipment, analyzes the sales data for the first ten years of his company to make decisions for thecompany's future. Data is only readily available for some of the years the company has been in business. Find an equation for theline of best fit, and use it to approximate the sales for the company's third year to the nearest dollar amount. [Note: the y-interceptis 1500, and the line passes through (10, 2100).]
A) $1550
B) $1650
C) $1680
D) $1700
Explanation:Using the y-intercept of $1,500 and the data from the tenth year, the equation of the line of best fit would be y = 60x + 1,500.Substituting x = 3 for the third year would result in sales of $1,680.
Which linear equation BEST represents the line of best fit for the scatterplot?
A) y = 1
3x - 1
B) y = -1
3x + 1
C) y = 3x + 1
D) y = 3x - 1
Explanation:The solution is y = 3x - 1. The slope is 3 and the y-intercept is -1.
30)
SEPARATE IMAGES Jeremy thinks that he drinks more water when it is hotter outside. For 11 weeks he records the averagetemperature for the week and his average daily water intake (in ounces). He then constructs a scatterplot and finds the line of bestfit. His line of fit has a small positive slope.
Which is most likely the scatterplot for this data set?
A)
B)
C)
D)
Explanation:Since the line of best fit has a small positive slope the graph needs be increasing, but not rapidly. As you move further out to theright on the x-axis, the y-values need to be increasing slightly. Since the description did say small, you want to choose the graphwith the smallest increase, which is graph C.
