# Normal Model

• March 25th 2008, 04:30 PM
Morgan82
Normal Model
A student tossed her coin 200 times, and found only 42% heads.

I know this is kinda low, but possible.

Can someone work all of this out and show me how to put it into a normal model with the SD and mean? Please explain? thanks
• March 25th 2008, 04:42 PM
bobak
Are you doing hypothesis testing ? Are you familiar with the binomial distribution ?

some pointers.

Let $X$ be the variable that represents the number of heads. We have $X \sim B(200, 0.5)$

Because you're using a large amount of trails you can use the Normal approximation $X \simeq \ \sim N (100 , 50)$

Bobak