Skip to content
MathsGenie logo
Quick links
Open app

Course home

  1. A Level
  2. Maths WJEC
  3. Question bank

4.2.2 Statistical distributions (A-level only)

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869
Question 51

The lifespan of a certain type of industrial LED, measured in hours, is assumed to follow a normal distribution with mean μ\muμ and variance σ2\sigma^2σ2. Based on data from a single random sample of these LEDs, a 99%99\%99% confidence interval for μ\muμ was calculated to be:

(11484.84,12515.16) (11484.84, 12515.16) (11484.84,12515.16)

Using the data from this same sample:

a.

Determine a 95%95\%95% confidence interval for μ\muμ.

[4]
b.

Eight independent random samples are subsequently collected, and a 95%95\%95% confidence interval for μ\muμ is constructed for each of these eight samples.

Calculate the probability that exactly 7 of these 8 intervals will contain the true population mean μ\muμ.

[3]

4.2.2 Statistical distributions (A-level only) Questions

  1. A Level
  2. /Maths
  3. /4.2.2 Statistical distributions (A-level only)