Skip to main content

Back to the full dot-point answer

Northern IrelandMathsQuick questions

AS 2 Applied Mathematics

Quick questions on Statistical distributions: discrete random variables and the binomial distribution - CCEA A-Level Mathematics

4short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is the mean of a binomial distribution?
Show answer
The mean (expected number of successes) of X∼B(n,p)X \sim B(n, p) is $E(X)=np.E(X) = np.Sooutof So out of 20trialseachwithsuccessprobability trials each with success probability 0.3,youexpect, you expect 20 \times 0.3 = 6$ successes on average.
What is q1?
Show answer
A random variable has P(X=1)=0.2P(X = 1) = 0.2, P(X=2)=0.5P(X = 2) = 0.5 and P(X=3)=pP(X = 3) = p. Find pp. [1 mark]
What is q2?
Show answer
State the mean of X∼B(50,0.2)X \sim B(50, 0.2). [1 mark]
What is q3?
Show answer
For X∼B(6,0.5)X \sim B(6, 0.5), find P(X=6)P(X = 6). [2 marks]

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All MathsQ&A pages