Answer:
The interval ( 1,8 ; 14,4 ) will contains 99,7 % of all values
Step-by-step explanation:
For Normal Distribution N ( μ ; σ ) the Empirical Rule establishes that in the intervals:
( μ ± σ ) we find 68,3 % of all values
( μ ± 2σ ) we find 95,4 % of all values
( μ ± 3σ ) we find 99,7 % of all values
Then we have a normal distribution N ( 8,1 ; 2,1 )
3*σ = 3* 2,1 = 6,3
And 8,1 - 6,3 = 1,8 8,1 + 6,3 = 14,4
Then the interval ( 1,8 ; 14,4 ) will contains 99,7 % of all values
