Answer:
18x +9h
Step-by-step explanation:
Such problems are tedious, but not difficult. The trick is to avoid making mistakes in the algebra.

Answer:
Both ends go up.
Step-by-step explanation:
Answer:

Step-by-step explanation:
Given
-- degree of freedom

Required
Determine the t-value
The given parameters can be illustrated as follows:

Where

So, we have:

To solve further, we make use of the attached the student's t distribution table.
From the attached table,
The t-value is given at the row with df = 28 and
is 3.673900
Hence, 
Answer:
7.065
Step-by-step explanation: