Question

The following scatter diagram shows two sets of data that show high positive correlation:
By drawing a line of best fit, and use interpolation to predict the value of $y$ when $x=4$

• A. $1.6$
• B. $9$
• C. $10$
• D. None of these

Answer 1

Answer: (B)

$9$

To predict $y$ value at $x=4$ consider $y$ values at $x=3$ and $x=5$ $(\because$ Interpolar $)$

At $x=3y=7.5$

$x=5y=10.5$

$(y-7.5)=\frac{(10.5-7.5)}{(5-3)}(4-3)$

$y-7.5=1.5$

$\therefore y=9$ at $x=4$