A team used the Ping Man robot to test golf balls. At one point, there was a mixed up that caused the team to end up with 20 unmarked balls in a basket. They knew that 7 balls were Snell MTB-X, 3 balls were Volvik S4, and 10 balls were Callaway Soft X, but they could not tell from looking at the balls. The team randomly got one of the balls and fed it to the robot. The ball went 284 yards. The team wants to use LDA to calculate the probability that the ball is Volvik S4.

The table below shows the average distances of golf balls when fed through a Ping Man robot from the past testings.

Brand	Average distance
Snell MTB-X	290 yards
Volvik S4	283 yards
Callaway Soft X	270 yards

*Standard deviation is 5 yards, same for all brands. The distances approximately follow a bell-shaped distribution.

What value should the team use for prior probability of Volvik S4?