Answer:
This is a reasonable decision because the sample size has no effect on the 90% confidence interval
Step-by-step explanation:
90% confidence interval
larger sample size = 20
condition : sample mean ( x-bar ) is the same for both samples
This is a reasonable decision because the sample size has no effect on the 90% confidence interval
from condition 1 :
Amount of drink dispensed is normally distributed with known standard deviation , given a random sample of n drinks and the sample mean at a confidence interval of 90%
for condition 2 :
sample size = 20
mean = 2.25 ( assumed value )
std = 0.15 ( assumed value )
Z = 1.645 ( Z-value )
determine the 90% confidence interval
= mean ± z [tex]\frac{std}{\sqrt{n} }[/tex]
= 2.25 ± 1.645 [tex]\frac{0.15}{\sqrt{20} }[/tex]
= 2.25 ± 0.0335 = ( 2.2835 , 2.2165 )
