1.

Given that a study uses statistical methods to conclude that there is an

association between the weights of cars and the amounts of fuel

consumption.
This means that the study established a correlation between

the weights of cars and the amounts of fuel

consumption.

But,

a correlation between variables, however, does

not automatically mean that the change in one variable is the cause of

the change in the values of the other variable.

Therefore, the conclusion by the study that adding weight to a car is

what makes it consume more fuel is wrong because The conclusion is based on a correlation that implies causality.2.

Given that a recent government agency found that 89% of people that owned a car

were above the poverty line, while only 8% of people that did not own a

car were above the poverty line. They concluded that owning a car kept

people out of poverty and started a program to give cars to people below

the poverty line.

We can see that the problem with the study is

that the government agency automatically assumed that the correlation

between the variables implies causality.

3.

Given that a government agency produced a study in which they randomly chose 100

students just beginning college to determine what percentage of students

who begin college graduate with a degree. After four years they

identified that 23 had dropped out of college, 45 had graduated, and 20

were still pursuing their degree.

Notice that the number of final sample is less than the number of the initial sample.

Therefore, What is wrong with this poll is that some of the sample data are missing.

4.

Given that a shampoo company recently paid a consulting firm to produce a study to

determine if using their product resulted in cleaner hair than other

brands.

As can be noticed the study is based on the self interest of the shampoo company.

Therefore, the thing wrong with this study is that it is a self-interest study.

5.

Given that a survey was recently quoted to support the news that the number of

trees in the United States is increasing. Upon further research it was

found that the survey was fully funded by a logging company.

As can be seen, the logging company funded the survey in other to justify their activities

Therefore, the problem with this survey is that it is a self-interest study.

6.

Given that a radio station sent a letter in the mail to 1000 randomly chosen

residents within its broadcast area. The letter contained one dollar and

a survey. The survey asked recipients to track their radio habits over a

week. The survey was to be filled out and sent back in to the radio

station.

Here, the major problem with this study is the problem of non-response.

There

is every possibility that not all the mails will be delivered either

way.

Therefore, a problem with the study is that a nonresponse occurred.

7.

Given that the fire department in California decided to take a poll to see if

residents would pay a monthly fee for their services. They polled 22

people in the state and concluded that residents were not willing to pay

a monthly fee.

As can be seen, a sample of 22 people is too small to refrect the views of the population of a state.

Therefore, what is wrong with this poll is that the conclusion is based on a small sample.

8.

Given that a campaign manager created a survey to see if the candidate could be

elected into office. The survey randomly chose 1,832 voters and asked

them whom they would vote for. Of those surveyed, 953 people responded

that they would vote for the candidate. Because there are 87,403 voters

in the area, the results mean that 45,466 people would vote for this

candidate.

As can be seen, the surveyor concluded that a similar

proportion of voters responded that they would vote for

the candidate, would vote for his

candidate. This is a precise number and surveys do not usually result in

a presice number but in a proportion with an allowed margin of error.

Therefore, a problem with the study is that the result is a precise number.

9.

Given that a hospital did a ten-year study on patients who used its services. One

thousand patients were randomly selected and followed over a period of

ten years to determine the average number of visits per year. By the end

of the ten year period some of the patients had left the area.

As

can be seen, because some of the patients had left the area, the

problem with the poll is that some of the sample data are missing.

10.

Given that a city council had a proposal for a new traffic light at an

intersection that had a recent accident. The council decided to take a

poll of 284 randomly selected residents and asked if they would support

the construction. Of those polled, 219 stated that they would support

the new traffic light and 45 said they would not.

Notice that the number of final sample is less than the number of the initial sample. (i.e. 219 + 45 = 264 which is less than 284)

Therefore, the problem

with the study is that some of the sample data are missing.