Skip to content

Course home

2.4.6 Probabilities using the normal distribution (A-level only)

2.4.6 Probabilities using the normal distribution (A-level only)

EasyMediumHard
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859
Question 51

A quality control technician monitors the viscosity, vvv centipoise (cP), of a batch of synthetic lubricant. The measured viscosity, VVV cP, follows a normal distribution with mean μ\muμ cP and standard deviation 3.23.23.2 cP.

a.

Find the probability that a single measurement of the viscosity is within 2.42.42.4 cP of the mean μ\muμ.

[2]
b.

The technician takes a random sample of 64 independent measurements.

Determine the probability that the sample mean of these 64 results, Vˉ\bar{V}Vˉ, is within 0.60.60.6 cP of μ\muμ.

[3]
c.

Given that the mean of these 64 measurements is 412.5412.5412.5 cP, calculate a 95%95\%95% confidence interval for μ\muμ, giving your limits to three decimal places.

[3]
Markscheme

2.4.6 Probabilities using the normal distribution (A-level only) Questions

  1. A Level
  2. /Maths
  3. /2.4.6 Probabilities using the normal distribution (A-level only)

147 exam-style questions on OCR A Level Maths 2.4.6 Probabilities using the normal distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank