Skip to content
MathsGenie logo
Quick links
Open app

Course home

  1. A Level
  2. Maths OCR (MEI)
  3. Question bank

2.4.13 Model with probability distributions

MediumHard
12345678910111213
Question 6

A viticulturist is investigating the survival of a new hybrid vine graft. The probability that a graft is successful is denoted by ppp. A sample of 100 grafts is taken, and the random variable S S\,S represents the number of successful grafts, where S∼B(100,p)S \sim \text{B}(100, p)S∼B(100,p).

Using a normal approximation, the probability that S S\,S is at least 53 is 0.0054 to 4 decimal places.

i.

Show that p p\,p satisfies 426.01p2−446.01p+110.25=0426.01p^2 - 446.01p + 110.25 = 0426.01p2−446.01p+110.25=0 when normal probability tables are used.

[6]
ii.

Hence find the value of ppp, justifying your answer.

[2]

2.4.13 Model with probability distributions Questions

  1. A Level
  2. /Maths
  3. /2.4.13 Model with probability distributions