Assuming the population has an approximate normal distribution, if a sample of size $n=20$ has a sample mean $\bar{x}=15$ and sample standard deviation $s=3$ What is the degree of freedom?
\( \boxed{19} \)
Step 1 :Given a sample size of \( n=20 \)
Step 2 :Calculate the degree of freedom as \( n-1 \)
Step 3 :Substitute the given value \( n=20 \) into the formula
Step 4 :Degree of freedom \( = 20 - 1 \)
Step 5 :Degree of freedom \( = 19 \)
Step 6 :\( \boxed{19} \)