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The Normal Distribution

The Normal Distribution

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Question 122

A commercial coffee machine dispenses espresso shots and steamed milk for lattes. The volume of an espresso shot, EEE ml, follows the distribution N(30.2,1.22)N(30.2, 1.2^2)N(30.2,1.22). The volume of a portion of steamed milk, MMM ml, follows the distribution N(220.5,4.52)N(220.5, 4.5^2)N(220.5,4.52). A barista prepares a "Large Latte" using a random sample of 3 espresso shots and 2 portions of steamed milk.

a.

Find the probability that the total volume of these 5 components exceeds 540 ml.

[4]
b.

A customer orders two portions of steamed milk to be served separately.

Determine the probability that the volumes of these two portions differ by more than 5 ml.

[3]
c.

To calibrate the machine, a technician takes a random sample of n+1n+1n+1 espresso shots with volumes E1,E2,E3,…,En+1E_1, E_2, E_3, \dots, E_{n+1}E1​,E2​,E3​,…,En+1​. The random variable TTT is defined as

T=nE1−∑r=2n+1Er T = n E_1 - \sum_{r=2}^{n+1} E_r T=nE1​−r=2∑n+1​Er​

Given that P(T>30)=0.0533P(T > 30) = 0.0533P(T>30)=0.0533 to 4 decimal places,

find the value of nnn.

[5]
Markscheme

The Normal Distribution Questions

  1. A Level
  2. /Maths
  3. /The Normal Distribution

616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.

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