Question

PLEASE HELP!!!!
Please explain why this is FALSE: "5. Using data from Boston, Massachusetts, a test of independence is run on the claim that ice cream sales per month and the number of car wrecks per month are independent. The claim is rejected.
Using number of car wrecks as the x variable and ice cream sales as the y variable, an r value of r=0.923 is then computed and shown to exceed the critical value for this data. The data is double checked and verified. This shows that car wrecks cause ice cream sales."

Answer 1

That r value is the key here

Answer 2

usually when it's this high (regardless of the critical value), it implies there's a strong correlation between the two variables

Answer 3

Okay

Answer 4

Oh, yes - I do remember learning that.

Answer 5

a strong correlation corresponds to the two variables being linked (one is independent and the other is dependent on that independent variable)

Answer 6

Makes sense, so far.

Answer 7

so they can't be independent if they are linked like this

Answer 8

that's why the claim that they are independent is rejected

Answer 9

Oh, I think I see what you're meaning - because the correlation (relationship) between "x" and "y" is so strong, both variables are dependent on each other, so it is not possible that they could be independent of each other?

Answer 10

that is close, it's more like "one variable dictates what the other variable is...so one variable is independent while the other depends on the first variable"

Answer 11

Okay

Answer 12

but yes, they are linked in a way that they can't be independent of each other

Answer 13

So, if the problem IS correct to have rejected the claim, what part of the problem is incorrect?

Answer 14

I'm not sure what you mean

Answer 15

oh i know what you're asking

Answer 16

Well, the instructions for the problem say it is false. I'm supposed to explain why it's false.

Answer 17

this is a very dangerous part of statistics because students often confuse correlation and causation

Answer 18

this is very important not to mix the two

Answer 19

if two variables are strongly correlated with each other, it doesn't necessarily mean that one causes the other

Answer 20

I should probably let you know that the last part of the problem says: NOTE: While this specific r-value is made up, this general pattern has been shown in several real world data sets involving ice cream sales and number of car wrecks in major cities on the east coast of the United States.

Answer 21

ie

correlation does NOT imply causation

Answer 22

I'm not sure if the NOTE is true or false (I don't know if my professor is saying that this part is false or true.

Answer 23

just because they both tend to decrease (for instance), doesn't mean that one causes the other to decrease as it decreases

Answer 24

does that make sense?

Answer 25

Yes! Thank you so much! I really appreciate that you took your time to help me! :) I understand it.

Answer 26

you're welcome