Algebra 1 Common Core Student Edition, Grade 8-9

Challenge 22. a. Make a scatter plot of th e d ata below. Then find th e eq u a tio n of the line of best

fit. Draw th e line of b est fit on your scatter plot.

Car Stopping Distances

Speed (mi/h) (^1015202530354045)
Stopping Distance (ft) 27 44 63 85 109 136 164 196
b. Use your eq u a tio n to p red ict th e stopping distance at 90 m i/h.
c. R easo ning The actual stopping distance at 90 m i/h is close to 584 ft. Why do you
th in k this distance is n o t close to your prediction?
d. Suppose you plot (90, 584) on your scatter plot. W hat effect w ould it have on the
slope an d y-intercept of the line of best fit you found in p a rt (a)?
St a n d a r d i ze d Test Pr ep
^SAT/ACT
Short

. R e s p o n s e
23. Suppose you survey each school in your state. W hat relationship would you expect
betw een the n u m b er of students an d the n u m b er of teachers in each school?
C/D positive correlation C O no correlation
CO negative correlation CO none of the above
24. A horizontal line passes through (5, - 2 ). W hich o th er po in t is also on th e line?
CD (5, 2) <D ( - 5 , - 2 ) C D ( - 5 , 2) CD (5, 0)
25. W hen 18 gal of w ater are p u m p e d into an em p ty tank, th e tan k is filled to three
fourths of its capacity. How m any gallons of w ater does th e tan k hold?
CAC 12 CD 13.5 CD 18.5 CD 24
26. The table shows th e balance of a stu d en t's b an k
acco u n t at various times. Estim ate how m u ch
m on ey is in th e stu d e n t’s b an k acco u n t in W eek 6.
Justify your answer.

W e ekly Account Balance

Week 13479

Account

Balance

m

$68 $85 $105 $136

f 1

Mixed Review

Write an equation of the line in slope-intercept form that passes through the See Lesson 5-6.

given point and is parallel to the graph of the given equation.

27. y = 5x + 1; (2, —3 ) 28. y = —jc — 9 ; ( 0 ,5) 29. 2x + 3y = 9; (-1 ,4)

Get Read y! To p r e p a r e f o r Lesso n 5 - 8 , d o Ex e r c i se s 3 0 - 3 3.

Find each absolute value. See Lesson 1-5.

30. |2 -7 | 31. |7 — 7| 32. 15 6 — 3 8 1 33. | —24 + 12|

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PowerAlgebra.com | Lesson 5-7 Scatter Plots and Trend Lines^343