Serum LDL conc are measured in blood sample collected from 100 healthy volunteers. The data follow normal distribution. The mean and standard deviation for this group is 130 mg/dl and 20mg/dl. Standard error of mean is 5.0. 95 % confidence interval about mean is 120 - 140 mg/dl. If blood samples are collected from 25 volunteers instead of 100, which of the following best expressed the expected impact on standard error and 95% confidence interval about the mean ?
Standard error Width of 95% CI
A. de de
B. de in
C de no change
D in de
E in in
F in no change
G no change de
H no change in
I no change no change
Standard error Width of 95% CI
A. de de
B. de in
C de no change
D in de
E in in
F in no change
G no change de
H no change in
I no change no change
