Course home

2.4.8 Normal distribution as a model (A-level only)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

Question 39

The life of a certain type of battery, $B$ hours, is normally distributed with a mean of 120 hours and a standard deviation of 16 hours.

Find $P (B > 144)$ .

[2]

Find the value of $k$ such that $P (B < k) = 0.15$ .

[3]

Ben is preparing for a 12-hour recording session. Given that the battery has already been in use for 144 hours,

find the probability that the battery will not run out before the session is completed.

[4]

Markscheme

2.4.8 Normal distribution as a model (A-level only) Questions

A Level
Maths
2.4.8 Normal distribution as a model (A-level only)

79 exam-style questions on OCR (MEI) A Level Maths 2.4.8 Normal distribution as a model (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

2.4.8 Normal distribution as a model (A-level only)

Question bank

2.4.8 Normal distribution as a model (A-level only)

Medium Hard

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

Question 39

The life of a certain type of battery, $B$ hours, is normally distributed with a mean of 120 hours and a standard deviation of 16 hours.

Find $P (B > 144)$ .

[2]

Find the value of $k$ such that $P (B < k) = 0.15$ .

[3]

Ben is preparing for a 12-hour recording session. Given that the battery has already been in use for 144 hours,

find the probability that the battery will not run out before the session is completed.

[4]

Markscheme

2.4.8 Normal distribution as a model (A-level only) Questions

A Level
Maths
2.4.8 Normal distribution as a model (A-level only)

79 exam-style questions on OCR (MEI) A Level Maths 2.4.8 Normal distribution as a model (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.