In: Statistics and Probability
Answer:
Project:
Analysis on the topic of the use of statistics in real life based
on real-life examples.
Statistical analysis two examples:
(1).
Linear regression quantifies the relationship between one or more
predictor variables and one outcome variable. Linear regression is
used for predictive analysis and modeling.
The table below shows some data from the early days of the Italian
clothing company Benetton. Each row in the table shows Benetton’s
sales for a year and the amount spent on advertising that year. In
this case, our outcome of interest is sales—it is what we want to
predict. If we use advertising as the predictor variable, linear
regression estimates that
Sales = 168 + 23 Advertising.
That is, if advertising expenditure is increased by one Euro, then
sales will be expected to increase by 23 million Euros, and if
there was no advertising we would expect sales of 168 million
Euros.
Year | Sales (Million Euro) | Advertising (Million Euro) |
1 | 651 | 23 |
2 | 762 | 26 |
3 | 856 | 30 |
4 | 1,063 | 34 |
5 | 1,190 | 43 |
6 | 1,298 | 48 |
7 | 1,421 | 52 |
8 | 1,440 | 57 |
9 | 1,518 | 58 |
(2).
t-test:
A t-test helps you compare whether two groups have different
average values (for example, whether men and women have different
average heights).
Example:
Let’s say you’re curious about whether New Yorkers and Kansans
spend a different amount of money per month on movies. It’s
impractical to ask every New Yorker and Kansan about their movie
spending, so instead, you ask a sample of each—maybe 300 New
Yorkers and 300 Kansans—and the averages are $14 and $18.
The t-test asks whether that difference is probably representative
of a real difference between Kansans and New Yorkers generally or
whether that is most likely a meaningless statistical fluke.
Technically, it asks the following:
If there were in fact no difference between Kansans and New Yorkers
generally, what are the chances that randomly selected groups from
those populations would be as different as these randomly selected
groups are.
For example, if Kansans and New Yorkers as a whole actually spent
the same amount of money on average, it’s very unlikely that 300
randomly selected Kansans each spends exactly $14 and 300 randomly
selected New Yorkers each spend exactly $18.
So if you’re sampling yielded those results, you would conclude
that the difference in the sample groups is most likely
representative of a meaningful difference between the populations
as a whole.
Thanks.