# Thread: finding z-statistic and P value

1. ## finding z-statistic and P value

Hello everyone! I just wanted to know if im doing this correct. The conclusion thing is quite confusing to me. I dont quite get how to find the level of significance.
Here's the problem and what i found so far(tell me if im wrong)

Statistics can help decide the authorship of literary works. Sonnets by a certain Elizabethan poet are known to contain an average of m=8.9 new words (words not used in the poet's other works). The standard deviation of the number of new words is s=2.5. Now a manuscript with 6 new sonnets has come to light, and scholars are debating whether it is the poet's work. The new sonnets contain an average of = 10.2 words not used in the poet's known works. We expect poems by another author to contain more new words, so to see if we have evidence that the new sonnets are not by our poet we test
H0: m = 8.9
Ha: m > 8.9

Give the z test statistic and its P-value. What do you conclude about the authorship of these new poems?

z = (10.2-8.9)/(2.5/2.4494879(square root of 6))
= 1.27
P(Z>1.27)= 1- .8980 = .102

after this, im kind of stuck.

Thanks so much for any help!!!!

2. Computationally, you did everything correctly.

You may want to check our Examples section which contains a short write-up on Hypothesis Testing (still "under construction" but contains good info), as well as our post containing Online Stats Resources.

Bottom line, there doesn't appear to be enough evidence to reject H0, assuming you want 95% confidence (which would set alpha at .05). Since P(Z >= 1.27) is > .05, then we cannot reject H0.

3. ## confused

How did you know to do P(Z>1.27), where did you get .8980 and why did you subtract it from 1?