Normal Distribution - Finding mean and st. dev : S1 Edexcel January 2011 Q8c : ExamSolutions Maths

[ShrewdEmpath]

Would you say that simultaneous equations are usually the way forward when you have two unknowns (e.g. sigma and mu?) I've noticed this in other papers too.

[Gamefreak]

great video, but i dont think you ever explained (did a video) on the percentage points normal distribution table in your s1 video tutorials. 

[techrando]

Really thank you for this tutor. that was really helpful

[umijasmine]

Thank you for clearing up my confusion.

[Creaxte]

This was great! Thank-you very much :D

[Gamefreak]

and also is the z2 number negative because 152 on the left side of the mean or is it because the area is less than 152 

[umijasmine]

Thank you for clearing up my confusion.