Algebra 1 Common Core Student Edition, Grade 8-9

Pr act i ce an d Pr o b l em - So l v i n g Ex er ci ses

Practice

MATHEMATICAL

PRACTICES

For each table, make a scatter plot of the data. Describe the type of correlation ^ See Problem 1.

the scatter plot shows.

7.

Jeans Sales

Average Price ($) 21 2 8 3 6 40

Number Sold 130

ta n

112

82 65

8.

Gasoline Purchases

Dollars Spent (^10119) ^ m _ J 8 13
Gallons Bought 2.6 I 3 2.4 2.2 3.5
Theme Parks Use the table below for Exercises 9 and 10. See Problem 2.
Attendance and Revenue at U.S. Theme Parks
Year 1990 1992 1994 1996 1998 2000 2002 2004 2006
Attendance (millions) 253 267 267 290 300 317 328 335
Revenue
(b illions o f dollars) 5.7 6.5 7.0 7.9 8.7 9.6 9.9 10.8 11.5
Source: In te rn a tio n a l A sso ciation o f A m u s e m e n t Parks a n d A ttra c tio n s

9. Make a scatter plot of th e d ata pairs (year, atten d an ce). Draw a tren d line an d write
   its equation. Estimate th e a tten d a n ce at U.S. th em e parks in 2005.


10. Make a scatter plot of th e d ata pairs (year, revenue). Draw a tren d line an d write its
    equation. Predict th e revenue at U.S. th em e parks in 2012.


11. Entertainm ent Use a graphing calculator to find th e eq u a tio n of th e line of b est ^ See Problem 3.
    fit for th e data in the table. Find th e value of th e correlation coefficient r t o t h r e e
    decim al places. Then p red ict th e n u m b e r of m ovie tickets sold in the U.S. in 2014.

Movie Tickets Sold in U.S. by Year

Year (^1998) : (^1999) ■;........: (^200020012002) .......................:^200320042005
...................
(^2006) ____ 2007
Tickets Sold
(m illions)^1289131113401339
1406 1421 1470 1415 1472 1470
Source: Motion Picture Association of America
Apply
In each situation, tell whether a correlation is likely. If it is, tell whether the
correlation reflects a causal relationship. Explain your reasoning.

12. th e a m o u n t of tim e you study for a test a n d th e score you receive


13. a p e rs o n ’s height a n d th e n u m b e r of letters in th e p erso n 's n am e


14. the shoe size an d th e salary of a teach er


15. th e price of ham b u rg er at a grocery store a n d th e a m o u n t of h am b u rg e r sold


16. Open-Ended D escribe th ree real-w orld situations: one w ith a positive correlation,
    one w ith a negative correlation, a n d one w ith no correlation.

See Problem 4.

PowerAlgebra.com I Lesso n 5-7 Scat t er Plo t s an d Tren d Lines^341