Date | November 2020 | Marks available | 3 | Reference code | 20N.1.AHL.TZ0.F_13 |
Level | Additional Higher Level | Paper | Paper 1 | Time zone | Time zone 0 |
Command term | Calculate | Question number | F_13 | Adapted from | N/A |
Question
Observations on 12 pairs of values of the random variables X, Y yielded the following results.
∑x=76.3, ∑x2=563.7, ∑y=72.2, ∑y2=460.1, ∑xy=495.4
Calculate the value of r, the product moment correlation coefficient of the sample.
Assuming that the distribution of X, Y is bivariate normal with product moment correlation coefficient ρ, calculate the p-value of your result when testing the hypotheses H0 .
State whether your -value suggests that and are independent.
Given a further value from the distribution of , , predict the corresponding value of . Give your answer to one decimal place.
Markscheme
use of
M1
A1
A1
Note: Accept any answer that rounds to .
[3 marks]
(M1)
A1
-value A1
Note: Accept any answer that rounds to or .
Note: Follow through their -value
[3 marks]
this value indicates that are not independent A1
[1 mark]
use of
M1
A1
putting gives A1
[3 marks]