What is a confidence interval?

Using the normal distribution, we can estimate a range of values which we expect to contain the mean. For example, if we take a sample of 30 students height, we can estimate the mean height of students in the year group to lie within a certain range.

We can use different values of the normal distribution to change the accuracy of the confidence interval, for example either the 99% confidence interval or the 90% confidence interval. The greater the percentage confidence we use, the wider the interval will be. 

AR

Related Maths A Level answers

All answers ▸

(https://qualifications.pearson.com/content/dam/pdf/A-Level/Mathematics/2013/Exam-materials/6666_01_que_20160624.pdf) Question 6.(i)


By consdering partial fractions find the integral of (1-x)/(5x-6-x^2) between x = 1 and x = 0, give your answer in an exact form.


Prove the trigonometric identity tan^2(x)+1=sec^2(x)


Differentiate sin(x)cos(x) using the product rule.