Confidence in Parameter

Question 1

Standard error of the mean

Answer 1

a measure of the dispersion of sample means around the population mean

Question 2

Calculating standard error of the mean

Answer 2

SD/sqrt(n-1)

+/- this value from the mean

Question 3

Student’s T-test

Answer 3

• used for comparing two sample means, where the samples are independent, the variables are constant and errors are normally distributed
• the number of standard errors by which the two sample means are separated

Question 4

Calculating student’s T-test

Answer 4

• rule of thumb is to take approx. 30 samples of each treatment
  BUT ONLY IF YOU CAN’T DO THE FOLLOWING:
  (8*variance in data)/(the square of the difference you want to detect)

Question 5

What confidence level do we use to find the mean + its uncertainty?

Answer 5

95%

- qnorm(0.975)* sd/sqrt(n)