One-tail & two-tail tests
Suppose we have a null hypothesis H0 and an alternative hypothesis H1. We consider the distribution given by the null hypothesis and perform a test to determine whether or not the null hypothesis should be rejected in favour of the alternative hypothesis.
There are two different types of tests that can be performed. A one-tailed test looks for an increase or decrease in the parameter whereas a two-tailed test looks for any change in the parameter (which can be any change- increase or decrease).
We can perform the test at any level (usually 1%, 5% or 10%). For example, performing the test at a 5% level means that there is a 5% chance of wrongly rejecting H0.
If we perform the test at the 5% level and decide to reject the null hypothesis, we say "there is significant evidence at the 5% level to suggest the hypothesis is false".
One-Tailed Test
We choose a critical region. In a one-tailed test, the critical region will have just one part (the red area below). If our sample value lies in this region, we reject the null hypothesis in favour of the
__________ _________ ___ _____ _______ ___ ____.
_____ _________ ________ __________ _______ _____ ________.
_____ __________ _________ ______ __________.
_______ ______ ___ ____ ______ __________ _____ ______ ___ ____ ___.
_________ _____ _____ ___ _____ ______ __________ _____ _______ _________ _____.
_______ __________ ___ _______ ___ _______ ___ _________ ______ _____ ______ ______.
_________ _____ ______ _______ __________ _________ ________ ______ ____ __________ __________ _____.
__________ _________ ______ ________ ___ _____ ____ ________ _____ ______ ________.
_____ _____ ___ _______ _________ _____ _________ _________.
_____ __________ ____ ______ _____.
_______ ______ __________ _____ ____.
________ _______ __________ _________ ______ ______ ______ ___ ___ _________.
______ ____ __________ __________ ______ _________ ________ __________ ____ __________.
____ _____ __________ _______ ________ _____ ______ ______ _____ ________.
__________ ____ _________ ______ _________ __________ ________ ________ ____.
____ _______ _________ __________ ________ _____ _______ _______ ________ ____.
____ ______ ______ ___ __________ _______ ___ ____.
___ __________ ___ ____ ______.
_____ ____ _______ _________ ___ ______ ____ _______ __________ _____.
__________ _______ _____ ________ _____ __________ __________ ____ ________ __________ _____.
__________ _________ ______ ____ __________ ________ _____.
________ __________ ______ __________ ____ ____ _________ _________ __________.
_________ ___ ______ _______ ___ _______ __________ ____ ____.
______ ________ _____ ________ _________.
______ __________ _______ ___ ________ __________ ___ ______ ___ ______.
_______ __________ __________ ________ ______ ________.
__________ ____ ___ __________ ______.
_____ ____ _______ _________ ___.
____ _________ _____ _________ ____ ________ _______ ________.
_________ _________ _______ _______ ______.
_______ ___ ___ ___ __________ __________.
_____ ______ _______ _________ _____ __________ __________ ___.
_______ _____ ______ _____ _______.
____ __________ ___ ___ _________ ____ _________ _____ ____.
________ ______ _______ ___ ________ _______.
___ ______ _____ ____ __________ ____ _____ ________ _____.
______ ________ __________ ______ ___ __________ __________.
__________ ________ ________ ________ __________ _________.
__________ ___ ______ ______ ___ _____ _________ ________.
____ ______ _________ ____ ____ ______ _________ ___ ________ _______ _______.
_________ __________ ___ ____ _________ _____ _____.
_________ ______ _______ ___ _____ ____ ______ ____ _________ ____ ___.
_______ _______ ____ __________ _____ _____ _________ __________ ___ __________.
______ ___ ________ ____ ______ ___.
_____ ______ ________ _______ _____ _______ ___ __________.
__________ _____ ____ _________ __________ _______.
_____ ____ _________ ______ ______ ______ _____ _______.
____ __________ _________ ________ ___ ________ ________.
________ _______ __________ __________ __________ ____ _________ _______.
_______ ___ ___ ______ ___ ___ ________ _____ _________ _____ ______.
__________ ___ _______ _____ _____ _________ ____ __________ ________ __________.
________ ________ _______ ______ __________ _________ _________ ________ _____ __________ ____ ______.
_______ _____ _______ ____ ____ ________ _________ __________ ___ _________ ___.
____ ____ ______ _______ ______ _________ ____ ________ _________.
___ ____ ________ _______ _________ ________.
___ ______.
- Solved Assignments
- Study Notes
- Guess Papers
- Question Papers
✓ Unlock up to 60% of the answer
✓ No payment required
Exponential Smoothing Method
Bayes' Theorem
Standard normal distribution:
Bayes' Theorem
Test of goodness of fit
Calculate the mean, median and mode from the following data relating to production of a steel mill for 60 days
The monthly incomes of a group of 10,000 persons were found to be normally distributed with mean equal to 
15,000 and standard deviation equal to 1000. What is the lowest income among the richest 250 persons?