IB Maths AA SL Topic 4: Statistics and probability questions

Exam-style questions in the shape of Paper 1 and Paper 2, with full markschemes. Read the markscheme, or type, photograph or draw your answer and get it marked.

Question 1

Paper 1, no calculatorEasy6 marks

A student records the average daily sunlight exposure, xx hours, and the height after four weeks, yy cm, of five seedlings of the same species.

xx23456
yy1112171718

For these data, the Pearson correlation coefficient is r=0.93r=0.93 and the regression line of yy on xx is y=1.9x+7.4y=1.9x+7.4

(a)

State the strength and direction of the correlation. State whether this result alone shows that sunlight causes greater height.

[2]
(b)

Use the regression line to estimate the height of a seedling receiving 5 hours of sunlight per day.

[2]
(c)

Interpret the gradient of the regression line in this context.

[1]
(d)

The observed sunlight exposures range from 2 to 6 hours per day. Explain why using the regression line to estimate the height at 10 hours per day may be unreliable.

[1]

Question 2

Paper 2, calculatorEasy5 marks

A student uses the spinner shown in Figure 1. Each of its six sectors is equally likely to be selected. Let AA be the event that the spinner lands on a number greater than 44

123456
(a)

List the outcomes in AA

[1]
(b)

Determine P(A)P(A)

[1]
(c)

State P(A′)P(A') where A′A' is the complement of AA

[1]
(d)

Determine the expected number of times the spinner lands on a number greater than 44 in 3030 spins.

[1]
(e)

In a separate trial of 3030 spins, the spinner lands on a number greater than 44 eight times. Calculate the relative frequency of AA

[1]

The best questions are still waiting

Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.