Someone please explain the margin error formula better. My class just gave it to me and said to practice.
1.96X Sq root((P(1-p))/N)

Question

Someone please explain the margin error formula better. My class just gave it to me and said to practice.
1.96X Sq root((P(1-p))/N)

amistre64 · Answer

would you agree that spread about the mean provides us with a range of options to choose from?

amistre64 · Answer

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amistre64 · Answer

if we wanted to find the spread about the mean that is some k% ... we would want to determine the z score related to that k% and find the values x0 and x1 that give us the boundaries of the spread.

amistre64 · Answer

therefore, using the zscore formula we get:$$\large z_{k\%}=\frac{x-p}{\sqrt{pq/n}}$$

$$\large z_{k\%}\sqrt{\left(\frac{pq}{n}\right)}=|x-p|$$

anonymous · Answer

But were do I put what?

amistre64 · Answer

well, they give you z_k%  as  1.96 (95% about the mean if memory serves)

the p,q,n parts deal with the specific proportion that you are playing with.

amistre64 · Answer

spose you take a survey and 6 out of 10 people like cheese.  the proportion, p, is therefore 6/10.  q is the complement of p, q=(1-p) = 4/10

and of course the number of people surveyed, n, is 10