Statistics

Exercice 1
A study conducts a census of all social housing in Montreal.
For this question, we are interested in the number of inhabitants per dwelling in Montreal.
Some dwellings are inhabited by 1 person, some dwellings have 2 occupants, etc.
For example, the study tells us that there are 1258 dwellings with 4 occupants.
We find in the study the following table:
Distribution of the dwellings according to the number of occupants
Number of occupants
Number of dwellings
1
1207
2
1755
3
1803
4
1258
5
2086
What is the standard deviation of the number of occupants per unit? Answer :
Show your reasoning here related to the previous question.
It is allowed to work on paper or in a program
Exercice 2
In a recent study by the Institut de la statistique du Québec, 673 young Quebecers reported having had
an average of 34.6 drinks during the month, with a standard deviation in responses of 5.7 drinks.
The sample consisted of 673 Quebecers aged 18 to 24 years, randomly selected from the population.
Using this information, estimate the average number of drinks for the population of young Quebecers,
with 99% confidence.
******
Your answer will be a complete sentence with a margin of error. If you are working on a piece of paper,
show your approach and give a complete sentence for the answer.
******
The margin of error on the mean is ± (Answer)
consumption, with 99% confidence.
Exercice 3
In a recent study by the Institut de la statistique du Québec, 673 young Quebecers reported having had
an average of 34.6 drinks during the month, with a standard deviation in responses of 5.7 drinks.
The sample consisted of 673 Quebecers aged 18 to 24 years, randomly selected from the population.
Using this information, estimate the average number of drinks for the population of young Quebecers,
with 99% confidence.
******
Your answer will be a complete sentence with a margin of error. If you are working on a piece of paper,
show your approach and give a complete sentence for the answer.
******
The margin of error on the mean is ± Answer
consumption, with 99% confidence.
Exercice 4
In deciding whether to continue studying, Tiago wonders if the years spent in school help him find a job.
He looks at a study that compares the experiences of 5 people with different levels of education who
looked for work during a period of unemployment. Here is a table that summarizes the number of years
spent in school and the number of days spent looking for work for each person.
Alex
Bea
Charles Denley Erika
10
13
12
16
21
Days of unemployment 48
59
31
35
32
Years of schooling
A) How much is the correlation coefficient that describes the strength of the relationship between years
of schooling and days of unemployment, and what does it mean?
B) Knowing that Tiago has 18 years of schooling, use linear regression to estimate the time he will spend
unemployed.
Ans: Statistically, using linear regression, we estimate that Tiago will spend
days unemployed.
Show your reasoning here related to the previous question.
It is allowed to work on paper