[Folks]

http://i45.tinypic.com/34hjs5d.png
In part c, where did the 0.5244 come from?

[Spellstheend]

The percentage points table, for 0.3

[mathswiz:)]

Your link isn't opening on my computer but the value of 0.3 in your tables would give you a z value of 0.5244...

[Negaduck]

You're doing what you did in (b) but for P(X>172) = 0.3

... I think.

I did S1 last year and doing S2 this year... S2 is all normal distribution.

[Folks]

(Original post by Spellstheend)
The percentage points table, for 0.3

(Original post by mathswiz:))
Your link isn't opening on my computer but the value of 0.3 in your tables would give you a z value of 0.5244...

Oh of course! Thank you!