Which can cause or introduce bias? (select all that apply)

a. response bias
b. wording
c. convenience sampling
d. voluntary sampling

b and c i belive. possibly A but not 100% sure

Sample Response: Each base must be treated separately. Since each base is raised to a negative exponent, they should both be in the denominator of the fractions. The simplified form of the expression has 1 in the numerator and r to the 8th power times s to the 5th power in the denominator.