# Maths Statistics 1 Question Problem.

Watch
Announcements
#1
[attach]8.050708050728051e+23[/attach] [attach]8.050708050728051e+23[/attach]
Can anyone explain me how 7.b) is solved.I am not understanding how 0.9426 is broken down to 0.9713 and .0287.
Paper Reference-2016 June S1 IAL
Last edited by Roha125; 2 years ago
1
2 years ago
#2
Sketch a normal curve, the midpoint of 1006 - w and w is the mean
the central area is 0.9426
due to symmetry, P(X < 1006-w) = 0.0287 and P(X > w) = 0.0287
https://imgur.com/a/k397rng

otherwise
z corresponding to 1006 - w = (503-w)/sigma
z corresponding to w = (w-503)/sigma
the probability is Φ[(w-503)/σ] - Φ[(503-w)/σ] = 2 Φ[(w-503)/σ] - 1
hence 2 Φ[(w-503)/σ] - 1 = 0.9426
so Φ[(w-503)/σ] is found
hence w is found
1
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Feeling behind at school/college? What is the best thing your teachers could to help you catch up?

Extra compulsory independent learning activities (eg, homework tasks) (23)
8.46%
Run extra compulsory lessons or workshops (39)
14.34%
Focus on making the normal lesson time with them as high quality as possible (46)
16.91%
Focus on making the normal learning resources as high quality/accessible as possible (38)
13.97%
Provide extra optional activities, lessons and/or workshops (79)
29.04%
Assess students, decide who needs extra support and focus on these students (47)
17.28%