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Approximating a Binomial Distribution

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Question 45

The continuous random variable TTT represents the deviation, in micrometres, of a high-precision digital caliper reading. The distribution of TTT is a continuous uniform distribution over the interval [0,2.5][0, 2.5][0,2.5].

a.

Determine P(T<1.0)P(T < 1.0)P(T<1.0).

[1]
b.

State the value of E(T)E(T)E(T).

[1]
c.

Calculate Var(T)Var(T)Var(T).

[2]
d.

A random sample of 20 readings taken by this caliper is recorded.

Find the probability that fewer than 9 of these readings show a deviation of more than 1.0 μm\mu \text{m}μm.

[3]
e.

For a different model of caliper, the deviation X μmX \, \mu \text{m}Xμm is represented by the cumulative distribution function F(x)F(x)F(x) defined by:

F(x)={0x<00.8x−0.16x20≤x≤2.51x>2.5 F(x) = \begin{cases} 0 & x < 0 \\ 0.8x - 0.16x^2 & 0 \le x \le 2.5 \\ 1 & x > 2.5 \end{cases} F(x)=⎩⎨⎧​00.8x−0.16x21​x<00≤x≤2.5x>2.5​

Using this model, find the value of P(X>1.0)P(X > 1.0)P(X>1.0).

[2]
f.

A large batch of 200 readings is collected from this different caliper.

Using a suitable approximation, find the probability that at least 80 of these readings show a deviation of more than 1.0 μm\mu \text{m}μm.

[4]

Approximating a Binomial Distribution Questions

  1. A Level
  2. /Maths
  3. /Approximating a Binomial Distribution

Practise Edexcel A Level Maths Approximating a Binomial Distribution with exam-style questions for A Level Maths. 68 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.

Question bank

Algebraic Methods
Functions and Graphs
Sequences and Series
Binomial Expansion
Radians
Trigonometric Functions
Trigonometry and Modelling
Parametric Equations
Differentiation
Numerical Methods
Integration
Vectors