Answer:
Step-by-step explanation:
Calculate z-score firstly
z-score = (x-mean)/SD = (2.75-2.5)/0.25 = 0.25/0.25 = 1
P( x greater than or equal to 2.75) = P(z greater than or equal to 1)
= 1 - p(z <1)
P(z<1) from table = 0.84134
1-p(z<1) = 0.15866 or 15.866%
The new mean age will be greater than 14.2 years because the teacher is older than the previous mean.
1/3 of a lap per 1 minute, 3 minutes per lap
