S2 ocr mei 2016

does this mean that youd use lambda for both the mean and the variance and then use the normal test? cos that what i did..?

This is what I can remember

Q1catter diagram:
1 mark for labelled axes, 2 marks for correctly plotted points
Spearmans: -0.366
Spearmans hypothesis test: accept H0.
Pearsons not appropriate since not bivariate normal because not elliptical.
No assumptions required for Spearmans.
1% significance level is 1% probability of rejecting H0 when it is in fact true.

Q2:
Independent: mutations dont affect probability of another mutation, random:mutations are unpredictable
Binomial calculation: 20C1 x 0.012^1 x 0.988^19 or something like that
Approximation to posission: mean = 500x0.012, then use tables etc.
Approximation to normal, mean=50000x0.012, variance=50000x0.012x0.998 then standardise and use tables etc.

Q3:
Simple normal calculations
Manufacturer claims over 95% etc.: calculate value= 0.9502 so claim is true.
Find sigma and mu, sigma =6350 and mu = 60500 or 50850 or something like that?
Draw distributions: X has lower mean and variance so less spread but taller
Calculate value of h when 99.9%: I got 40500 or there abouts

Q4:
Calculate expected frequency of female and likes maths, show contribution=...
Chi test, add up contributions, accept H0.
Normal test, calculate mean and variance or standard distribution, calculate test statistic, reject H0.

If any one remembers anything else let me know.