use a standard normal distribution table to find a z score such that 36% of the area under the standard normal curve is below that score.

Question

anonymous · Answer

someone please help

tkhunny · Answer

It's 36%.  That's less than 1/2, so we seek a negative z-score.

Empirical rules suggests that z = -1 puts 16% in the left tail, so we shoudl be closer to zero than z = -1.

What tools have you to calculate a more precise value?

anonymous · Answer

I just have a normal distribution table

tkhunny · Answer

A picture?  It should have one tail or the other shaded.

anonymous · Answer

attachment

tkhunny · Answer

Perfect.  You just have to find the value 0.3600 in the body of the table and read the answer from the row and column labels.

anonymous · Answer

would the 0.3594 count as that? I cant find a 0.3600

anonymous · Answer

in that case it would be -0.36

tkhunny · Answer

That is a common problem.  You have to decide what to do.

1) Get as close as possible, or
2) Learn to interpolate between the two closest values.

I get an exact value (off a calculator) of -0.3584588.  Your well-selected value of -0.36 is right on!  Excellent work.

anonymous · Answer

but that seems too easy, 36% works out to -0.36. is that normal?

tkhunny · Answer

Only a coincidence.  Don't count on it happening too ofte,  One is increasing and the other decreasing.  It crosses at about 0.35958 but NOWHERE else.

anonymous · Answer

ok, thanks!