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 ▸

Integrate cos^2A


How to differentiate tan(x)?


Given that: 2tanθsinθ = 4 - 3cosθ , show that: 0 = cos²θ - 4cosθ + 2 .


The region R is bounded by the curve y=sqrt(x)+5/sqrt(x) the x-axis and the lines x = 3, x = 4. Find the volume generated when R is rotated through four right-angles about the x-axis. Give your answer correct to the nearest integer.