Respuesta :
Answer:
P[ X < 2,4 ] = 0,1587 or 15,87 %
Step-by-step explanation:
Normal Distribution N ( 2,6 , 0,2 )
mean = μ₀ = 2,6 ft and
standard dviation is
σ = 0,2 ft
Samle size 53 n = 53
2,4 - 2,6 = 0,2
That means the difference between 2,4 and the mean of the sample ( 2,6) is equal to one standar deviation. The empircal rule establishes that the interval [ μ₀ ± σ] contans 68,3 % of all values, by symmetry
μ₀ - σ = 68,3/2
μ₀ - σ = 34,15
Then the half of the bell shape curve is 0,5 and from 0,2 up to 0 ( the normalized μ₀ ) is 34,15 then dfference between
0,5 - 0,3415 = 0,1585 or 15,85% is the probability
Other procedure is:
P[ X < 2,4 ] = [X - μ₀ ] / σ
P[ X < 2,4 ] = 2,4 - 2,6 / 0,2
P[ X < 2,4 ] = - 0,2/0,2
P[ X < 2,4 ] = - 1
And fom z - table we find for z (score) = - 1
P[ X < 2,4 ] = 0,1587
Answer:
0.0668
Step-by-step explanation:
z=x−μσ=2.3−2.60.2=−1.50
Using the normal distribution tables, we find that the area under the standard normal curve to the left of z=−1.50 is approximately 0.0668. Thus, the probability that an individual man’s step length is less than 2.3 feet is approximately 0.0668.
