Hypothesis

Question 1

What is hypothesis

Answer 1

A hypothesis is an assumption about one or more population parameters, which may or may not be true

Question 2

Steps in Hypothesis Testing

Answer 2

(1) Formulate the null and alternative hypotheses
(2) Specify the level of significance. What is level of significance? What are the conventional values? Note: once the level of significance is known, the level of confidence is implied
(3) Specify the test statistic
(4) Specify the decision rule
(5) Compute the Test statistic
(6) Present the results
(7) Make the decision
(8) State the implication

Question 3

Errors in testing hypotheses
When we test hypotheses, as much as possible, we try to minimize errors. But since we are not God, we make provision for errors through the specification of the level of significance. There are two possible errors that may arise
Which are

Answer 3

Type I Error; and
Type II Error

Reject H_0 Do not reject H_0
(i.e. Accept H_0)
H_0 is True Type I Error Correct Decision
H_0 is false Correct Decision Type II Error

Question 4

Z calculated Or t calculated =

Answer 4

(X ̅-µ)/(σ/√n) (Xbar minus nu)/sigma/square root of n
Where X ̅ = sample mean
µ = population mean
and n = sample size

Question 5

When do you reject H0

Answer 5

Reject h0 if Z calculated < -z tabulated

Reject h0 if z calculated > tabulated

Question 6

Difference between one tailed and 2 tailed test

Answer 6

For example, we may wish to compare the mean of a sample to a given value x using a t-test. Our null hypothesis is that the mean is equal to x. A two-tailed test will test both if the mean is significantly greater than x and if the mean significantly less than x.

A one-tailed test is appropriate if you only want to determine if there is a difference between groups in a specific direction.

Question 7

What test do you use for population variance unknown sample size small

Answer 7

T test

Question 8

How to get t tabulated at a particular level of significance

Answer 8

TѲ,n-1

N-1 refers to the degrees of freedom of the one sample t test

Question 9

Testing two population means

Formula for z calculated when population variances known

Answer 9

X1-x2
———-
Square root of

Ѳ^2. Ѳ^2
—- +. ——
n1. n2

Question 10

Testing two population means
Formula for z calculated when population variances Unknown but sample size large
n1 plus n2= 60
Test statistics z

Answer 10

X1-x2
———-
Square root of

S1^2. S2^2
—- +. ——
n1. n2

Question 11

Testing two population means
Formula for z calculated when population variances Unknown but sample size large
n1 plus n2 < 60
Test statistics t

Answer 11

X1-x2
———-
Square root of
(n1-1)s1^2 + (n2-1)s2^2
———————————-  (1/n1 + 1/n2)
     n1 +n2^-2

Question 12

If equal variances are assumed then t tabulated has v degrees of freedom where v=

Answer 12

V=n1+n2-2

Question 13

If equal variances are not assumed then v=

Answer 13

V=