Question

Help ! i got this question wrong in test

Answer 1

Question 5

A random sample of 100 runners who completed the 2012 Cherry Blossom 10 mile run yielded an average completion time of 95 minutes. A 95% confidence interval calculated based on this sample is 92 minutes to 98 minutes. Which of the following is false based on this confidence interval?

Answer 2

options :


a) The margin of error of this confidence interval is 3 minutes.

b) 95% of the time the true average finishing time of all runners who completed the 2012 Cherry Blossom 10 mile run is between 92 minutes and 98 minutes.

c) We are 95% confident that the true average finishing time of all runners who completed the 2012 Cherry Blossom 10 mile run is between 92 minutes and 98 minutes.

d) Based on this 95% confidence interval, we would reject a null hypothesis stating that the true average finishing time of all runners who completed the 2012 Cherry Blossom 10 mile run is 90 minutes.

Answer 3

based on given confidence interval (92, 98),
\(\overline{x} = 95\)
\(ME = 3\)

so that eliminates option a

Answer 4

all other options look valid to me :/

Answer 5

I would say c) is false, due to the way it is worded. Were you given the correct answer?

Answer 6

ohk that makes some sense but not entirely sure..
no, i dont have answer yet... i ticked option a by mistake in the exam and it was wrong

Answer 7

c) is the false statement. A confidence interval does not have the meaning stated in c).

Answer 8

okay i think so, the concept still dint sink in my head properly... care to elaborate a bit

I thought 95% confidence interval means : The interval captures \(\mu\), 95% of the time correctly ?

Answer 9

based on that, c looks fine to me ?
a and d looks fine aswell... to me all options look valid :/

Answer 10

The difference between b) and c) is in the first part of the statements:

b) - 95% of the time ...
c) - we are 95% confident ...

The basic definition of a confidence interval is that if you repeat an experiment a large number of times, a certain percentage of the resulting values will fall within a given range. This definition corresponds with b) but not with c).

Just being "95% confident" as c) states is not the correct way of saying it.

It's a little confusing but it'll probably start making more sense if you do some more reading on what a confidence interval is.

Hope this helps.

Answer 11

thank you i think i get it :)

Answer 12

il go wid option C thanks again !!!

Answer 13

You're welcome :)