Question : in T-sql how to find 80% a one value based on other

i have joined view and a table. I have following 4 columns

ProjectName  Quoted   Actual    Balance

in my t-sql script i have a case as below. I want to find:

When Actuals  are less then Quoted
and Actual which have exceed 80% of Quoted.

I am entering the following case however i am getting convert to varchar or numeric error prompt, please can you fix the below statement



CASE
WHEN actual < quoted and WHEN actual >(quoted * .80)

Answer : in T-sql how to find 80% a one value based on other

what are the data types of the 2 columns?
also, you "requested logic" seems incorrect?