"Ten Dollar Ride" joke

Stumpy Grinder and his wife Martha were from Portland, Maine.
Every year they went to the Portland Fair, and every year Stumpy
said, "Ya know Mahtha, I'd like ta get a ride in that theah aihplane."
And every year Martha would say, "I know Stumpy, but that aihplane
ride costs ten dollahs.... And ten dollahs is ten dollahs."
So Stumpy says, "By Jeebers Mahtha, I'm 71 yeahs old. If I don't go
this time I may nevah go." Martha replies "Stumpy, that there aihplane
ride is ten dollahs... and ten dollahs is ten dollahs."
So the pilot overhears them and says, "Folks, I'll make you a deal,
I'll take you both up for a ride. If you can stay quiet for the entire ride
and not say one word, I won't charge you, but just one word and it's ten
dollars."
They agree and up they go.... The pilot does all kinds of twists and
turns, rolls and dives, but not a word is heard. He does it one more
time; still nothing.... So he lands.
He turns to Stumpy as they come to a stop and says, "By golly, I did
everything I could think of to get you to holler out, but you didn't."
And Stumpy replies "Well, I was gonna say something when Mahtha fell
out... but ten dollahs is ten dollahs!"