NZ Level 7 (NZC) Level 2 (NCEA) Interpreting Information from Fitted Lines II

## Interactive practice questions

A least squares regression line is given by $y=3.59x+6.72$y=3.59x+6.72.

a

State the gradient of the line.

b

Which of the following is true?

The gradient of the line indicates that the bivariate data set has a positive correlation.

A

The gradient of the line indicates that the bivariate data set has a negative correlation.

B

The gradient of the line indicates that the bivariate data set has a positive correlation.

A

The gradient of the line indicates that the bivariate data set has a negative correlation.

B
c

Which of the following is true?

If $x$x increases by $1$1 unit, then $y$y increases by $3.59$3.59 units.

A

If $x$x increases by $1$1 unit, then $y$y decreases by $3.59$3.59 units.

B

If $x$x increases by $1$1 unit, then $y$y decreases by $6.72$6.72 units.

C

If $x$x increases by $1$1 unit, then $y$y increases by $6.72$6.72 units.

D

If $x$x increases by $1$1 unit, then $y$y increases by $3.59$3.59 units.

A

If $x$x increases by $1$1 unit, then $y$y decreases by $3.59$3.59 units.

B

If $x$x increases by $1$1 unit, then $y$y decreases by $6.72$6.72 units.

C

If $x$x increases by $1$1 unit, then $y$y increases by $6.72$6.72 units.

D
d

State the value of the $y$y-intercept.

Easy
Approx a minute

A least squares regression line is given by $y=-3.67x+8.42$y=3.67x+8.42.

The following scattergraph shows the value of various $4$4 bedroom, $2$2 bathroom homes in a new suburb.

The price of various second-hand Mitsubishi Lancers are shown below.

### Outcomes

#### S7-2

S7-2 Make inferences from surveys and experiments: A making informal predictions, interpolations, and extrapolations B using sample statistics to make point estimates of population parameters C recognising the effect of sample size on the variability of an estimate

#### 91264

Use statistical methods to make an inference