# PS295 Study Guide - Quiz Guide: Scatter Plot, Null Hypothesis, Round-Off Error

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Name ________________________ ID# ____________

Lecture section ________ Lab Section #_______

PS296 Assignment 5 Due: Monday April 8

Note: If you do not provide your correct Lab Section above, you will lose 1 point. This assignment, like the previous

assignments, is due at the beginning of class time. If you are late to class, or if you hand it in after the start of class, it

will be marked late; if you have previously submitted an assignment late, the TA will still mark this assignment and

provide feedback, but you will receive a grade of zero for this assignment.

For each calculation question (starting with 1e), you must show the formula used, the

substitution of numbers into the formula, and your final answer (rounded off to two

decimal places).

1a) The data given below represent the age (in years) and asking price (in thousands of

dollars, rounded off) for a sample of 12 used Toyota Corollas (silver exterior, automatic

transmission) advertised in AutoTrader magazine on a randomly chosen day.

Calculate the means of X and Y and complete the calculations in the table, including the

column sums on the bottom row.

Age

(X)

Price

(Y)

()XX

()YY

2

()XX

2

()YY

( )( )X X Y Y

X2

Y2

XY

3

19

1

19

1

17

2

16

2

15

4

14

3

14

2

14

4

11

5

10

4

10

5

9

2

1b) On the graph below complete the scatterplot of the Toyotas’ ages (0-5 years) on the X

axis against their asking price (9-20 $K) on the Y axis.

Draw a rough best-fitting straight line through the plot, making sure it passes through

the point

YX ,

.