Variables, other than the independent variables, that influence the response of the test units are called extraneous variables

In 2017, Smith paid $6,000 to the tax collector of Big City for realty taxes on a two-family house owned by Smith's mother. Of this amount, $2,800 covered back taxes for 2016, and $3,200 covered 2017 taxes. Smith resides on the second floor of the house, and his mother resides on the first floor. In Smith's itemized deductions on his 2017 return, what amount was Smith entitled to claim for realty taxes?

a. $6,000 b. $3,20 c. $3,000 d. $0

Scientific reports are tightly controlled by _____________________

a. page length b. scientific convention and tradition c. scientific governing bodies d. federal legal requirements