"What Is Pi" joke

"What is Pi?"
A mathematician: "Pi is the ratio of the circumference of a circle to its diameter."
A computer programmer: "Pi is 3. 141592653589 in double precision."
A physicist: "Pi is 3. 14159 plus or minus 0. 000005."
An engineer: "Pi is about 22/7."
A nutritionist: "Pie is a healthy and delicious dessert!"