Jaspreet | Prabhakaran | Tanya | Prashant
A mathematical comparison between expected frequencies and observed frequencies which are developed on the basis of two main hypotheses.
1) Null Hypothesis
2) Alternative Hypothesis
A researcher plans to ask employees whether they favour,
oppose or are indifferent about a change in the company’s superannuation provider.
How can we formulate a null hypothesis for a Chi-Square test to determine
the expected frequency for each answer.
1) We assume that the Null Hypothesis is true
3) The expected frequency is an equal distribution i.e. 1/3 of 75 for each available response
2) We have chosen a random sample of 75 employees
Suppose the observed responses to the proposed survey in
Q:1 were: Favour – 30, Oppose – 15, Indifferent – 25.
How can we perform a Chi-Square test based on these observed responses and the expected frequencies provided in the previous question?
Calculation of Chi-Square Test
Outcomes of Chi-Square Test
Determination of Significance Value (α)
The following is a summary of typical types of data that might be received
from a questionnaire to discover the local populations agreement and
disagreement with the success of the new neighborhood
initiatives designed to enhance well being.
Determine a statistical hypothesis and perform a Chi-Square test on the data.
Public Transport Facilities in the Neighbourhood have improved over the last year.Public Transport Facilities in the Neighbourhood have improved over the last year.
Public Transport Facilities in the Neighborhood have improved over the last year.
Agree - 20
Neutral - 36
Disagree - 28
Total - 84
Generally speaking, there is less rubbish lying around the neighborhood now than a year ago.
Agree - 48
Neutral - 22
Disagree - 12
Total - 82
What are the statistical decisions that can be made if there is a change in the significance level?