Practise questions · Salam Academy

SA-IAL-S1-CR-0081 markL1 FoundationCalculatorUsing the line

A scientist sets the temperature of a liquid and measures how long a reaction takes. Which is the explanatory variable?

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR2-0011 markL1 FoundationNon-calculatorRegression line

For a set of data,

S_{xx}=12

and

S_{xy}=30

. Find the gradient

b

of the regression line of

y

on

x

.

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR2-0022 marksL1 FoundationNon-calculatorRegression line

The regression line of

y

on

x

has gradient

2.5

. Given

\bar x=4

and

\bar y=13

, find

a

.

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR2-0031 markL1 FoundationNon-calculatorUsing the line

Use the regression line

y=3+2.5x

to estimate

y

when

x=6

.

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR2-0041 markL1 FoundationCalculatorUsing the line

A taxi fare

y

dollars is modelled by

y=2.5+0.8x

, where

x

is the distance in km. What does

0.8

represent?

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR2-0051 markL1 FoundationCalculatorUsing the line

A gardener gives plants different amounts of fertiliser and measures their heights. The response variable is

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR-Q021 markL1 FoundationCalculatorRegression line

The regression line of

y

on

x

always passes through

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR-0034 marksL2 StandardCalculatorRegression line

For

8

pairs of values,

\sum x=48

,

\sum y=120

,

S_{xx}=32

and

S_{xy}=40

. The regression line of

y

on

x

is

y=a+bx

. Find

b

and

a

.

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR-0043 marksL2 StandardCalculatorUsing the line

The regression line

y=7.5+1.25x

was found from data with

x

between

2

and

10

. (i) Estimate

y

when

x=7

. (ii) Which estimate would be unreliable?

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR-0063 marksL3 ExamCalculatorUsing the line

The regression line of

y

on

c

is

y=12+3c

, where

c=\dfrac{x-20}5

. The regression line of

y

on

x

is

y=a+bx

. Find

a

and

b

.

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR-0096 marksL3 ExamCalculatorRegression line

The table shows five pairs of values.

x

:

1,\ 2,\ 3,\ 4,\ 5

.

y

:

3,\ 5,\ 4,\ 7,\ 8

. (i) Find

r

, to 3 significant figures. (ii) Find the regression line of

y

on

x

in the form

y=a+bx

.

Salam Academy Original Practice · Proposed mark scheme

SA-IAL-S1-CR2-0063 marksL3 ExamNon-calculatorUsing the line

A coded regression line is

d=2+0.5c

, where

c=x-10

and

d=\dfrac y{10}

. Find the regression line of

y

on

x

in the form

y=a+bx

.

Salam Academy Original Practice · Proposed mark scheme

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