S2 Edexcel-What way is best for hypothesis testing??Watch
1-0.8645=0.1355 which is greater than the 5percent level so there is insufficient evidence to reject H null in favour of H1??? Both ways give a correct solution.
And also when you rewrite PDFs--->CDFs I always get the inequality signs muddled in a sense they are right but I miss a "less than or equal to" sign or "greater than or equal" and just leave it as "greater than." Is this penalised in the exam??
For example Jan 2002 S2 paper Question 2. Would it be better to find the critical region for hypo to be true(which is X>=16) or the way I do it which is to find null hypo and H1 use the X follows Poisson 10 bit cos of the 4 weeks and then proceed
Let X be the random variable "the number of houses sold in 4 weeks"
P(X>=14) = 1 - P(X<=13)
from tables: 1-0.8645 = 0.1355
which is greater than 0.05, and thus is not significant