When testing

\\\\mu

, how do we decide whether to use the standard normal distribution or a Student's

t

distribution?\ If the

x

distribution is normal and

n>=20

with known

\\\\sigma

we use the standard normal. With the same conditions and unknown

\\\\sigma

we use the Student's

t

.\ If the

x

distribution is normal and

n~~30

with known

\\\\sigma

we use the standard normal. With the same conditions and unknown

\\\\sigma

we use the Student's

t

.\ If the

x

distribution is normal and

n>=30

with known

\\\\sigma

we use the Student's

t

. With the same conditions and unknown

\\\\sigma

we use the standard normal.\ Whenever we assume the populations are independent, we always use the standard normal.

When testing , how do we decide whether to use the standard normal distribution or a Student's t distribution? If the x distribution is normal and n20 with known we use the standard normal. With the same conditions and unknown we use the Student's t. If the x distribution is normal and n30 with known we use the standard normal. With the same conditions and unknown we use the Student's t. If the x distribution is normal and n30 with known we use the Student's t. With the same conditions and unknown we use the standard normal. Whenever we assume the populations are independent, we always use the standard normal