TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Tetrachoric correlation is _ artificially dichotomous variables.

SOLUTION: two

PROBLEM: Unipolar motors have _ coils and are likely to have five or six wires attached.

SOLUTION: four

PROBLEM: Cryptography provides _ services that are crucial in secure programming.

SOLUTION:
three