Question

Check Elementary statistics. Two questions

Answer 1

Im getting the first answer "-1.85" but im getting "-1.010" for the second one

Answer 2

d with a line over it : -1.431

tc= 1.782

Ed= -19.3
Ed^2= 35.31

Sd= 0.851

Answer 3

-1.431- 1.782 (0.851 divided by square root 13)= -1.85

-1.431+1.782 (0.851 divided by square root 13)= -1.010

Answer 4

Where did I wrong? Or is the systems answer incorrect?

Answer 5

@Directrix @abb0t @zepdrix

Answer 6

Let me get my calculator.

Answer 7

Okay

Answer 8

I have to go, I will be back in a hour, I apologize.
If you still need help on this one, I will gladly help.

Answer 9

Okay. Thats fine

Answer 10

@Vuriffy

Answer 11

Is \(-1.12\) as in your screenshot getting accepted?

Answer 12

What?? .. I did not put an answer down for this question. So it marks it red. The system says thats the answer

Answer 13

Well your computation is correct, so if it's not getting accepted the system is probably at fault.

Answer 14

Okay. Would you mind checking another?

Answer 15

Part B I got the answer: 0.977

Answer 16

Ex= 21
Ey= 7470
Exy= 33650

Ex^2= 91
Ey^2= 12671900

Answer 17

The Pearson system says the answer is 0.975

Answer 18

@HolsterEmission

Answer 19

What's the formula you're using to compute the correlation coefficient? The numbers you list above give me a different value, about \(1.00291\), which I'm getting using the formula listed at the bottom of the "population" subsection here: https://en.wikipedia.org/wiki/Pearson_product-moment_correlation_coefficient#For_a_population

Answer 20

Look under chapter 9

Answer 21

Alright, so you must be using the formula for a sample. The experiment is conducted for \(6\) children, so \(n=6\). Adjusting my calculation for that, I'm getting just \(1\) but that clearly disagrees with the expected solution...

Answer 22

Okay

Answer 23

By "Ex" do you mean \(\sum x\)?

Answer 24

Or is the "E" for expected value, \(E(x)\)?

Answer 25

The first one

Answer 26

Oh, hold on, I've been carrying out the wrong computation... (product instead of sum -_-)

I am getting \(0.975\) now. I believe the problem lies in how you got the values you listed earlier. You should be getting
\[\sum xy=33800\\
\sum x=21\checkmark\\
\sum x^2=91\checkmark\\
\sum y=7500\\
\sum y^2=12800000\]

Answer 27

Hmm okay let me look back over them

Answer 28

I put 2120 down on my paper instead of 2150. Thats why everything is off

Answer 29

Alright now I have the correct answer. Thanks

Answer 30

yw