A2 statistics practice (i need solving questions 5-7)

5. Given a specific value of , the corresponding value is obtained from

You're given and that when . This means

6. Same as 3 and 4. I assume you have a calculator you can use to find . You should get around 0.9878.

7. We're told that 18.72 is 1.5 standard deviations below the mean of 31.5. This translates to

step-by-step explanation:

first, eliminate the parenthesis:

3

x

+

2

−

4

x

second, group like terms:

3

x

−

4

x

+

2

third, combine like terms:

(

3

−

4

)

x

+

2

→

−

1

x

+

2

→

−

x

+

2

goog may have it for you