Download 14_Normal_distribution_B

.
Continuity Correction
Σ (new) Ex 23.02
(old) Ex 17.02
.
The normal distribution models a CONTINUOUS variable
The normal distribution can be used to approximate DISCRETE variables
eg. When data is rounded eg to the nearest cm
eg. When the Normal distribution is used to model the Binomial or Poisson
distributions
0.2
0.2
0.15
0.15
0.1
0.1
0.05
0.05
0
0
0
0
2
4
6
8
10
12
Distribution of discrete data
P(x > 6)
14
2
4
6
8
10
12
14
16
16
Distribution of continuous data
= P(x>6.5) continuity correction
P(x
 12)
= P(x<12.5) continuity correction
P(x
 8)
= P(x>7.5) continuity correction
maths.nayland.school.nz
.Ex 17.2 p 362.
2) Weight of pumpkin (to nearest kg) Mean = 22 kg, Standard deviation = 3kg
P(x > 20kg)
3) Mean temperature is 6°C Standard deviation = 4°C
Temp measured to nearest degree.
P(At least 0°C)
6) Mean Time for snooker is 25min, Standard deviation = 4 min
Time measured to nearest minute.
a) P(Less than 28min)
b) P(30min)
maths.nayland.school.nz