Suppose a random sample of 84 men has a mean foot length of 26.9 cm with a standard deviation of 2.1 cm. What is an 80% confidence interval for this data?

Question 21 options:

A.) 21.52 to 32.28

B.) 28.58 to 25.22

C.) 24.21 to 29.59

D.) 24.8 to 29

Question

Suppose a random sample of 84 men has a mean foot length of 26.9 cm with a standard deviation of 2.1 cm.  What is an 80% confidence interval for this data?

Question 21 options:
	
A.) 21.52 to 32.28

	
 B.) 28.58 to 25.22

	
C.) 24.21 to 29.59

	
D.) 24.8 to 29

amistre64 · Answer

we would need a zscore that relates to one of the end points .... (1-.8)/2  might get us the necessary value for an invNorm function, or a field value in the z table

anonymous · Answer

Im sorry, but i don't understand what you are asking..

amistre64 · Answer

ok, then what is your method for finding confidence intervals?

amistre64 · Answer

and i wasnt asking stuff, i was giving information that could be useful

amistre64 · Answer

we are centering an interval about the mean such that 40% is to the left and 40% is to the right

since 50% of the data is on either side of the mean .... we need a zscore (maybe called a standard score in your material) ... that relates to .5-.4= .1

if this means nothing to you, then you may need to review your material.

anonymous · Answer

i got the answer now, thanks for your help.