Respuesta :
Answer:
a) P ( - 1.96 < Z < 1.96 )
b) P ( - 2.58 < Z < 2.58)
c) P ( -0.995 < Z < 0.995 )
d) P ( - z < Z < z ) = P ( ( Z ± 3σ ) then that is close to 1
Step-by-step explanation:
a) P ( - z < Z < z ) = P ( - 1.96 < Z < 1.96 )
CI = 95 % significance level α = 5 % α = 0.05 α/2 = 0.025
z = 1.96
b) P ( - z < Z < z ) = P ( - 2.58 < Z < 2.58)
CI = 99 % significance level α = 1 % α = 0.01 α/2 = 0.005
z = 2.58
c) P ( - z < Z < z ) = P ( -0.995 < Z < 0.995 )
CI = 68 % significance level α = 32 % α = 0.32 α/2 = 0.16
z ≈ 0.9954
We interpolate in this case
1 ⇒ 0.1587
0.99 ⇒ 0.1611
0.01 ⇒ 0.0024
x ⇒ 0.0013 x = 0.01 *0.0013 / 0.0024
x = 0.005416
and z = 0.99 + 0.005416
z = 0.9954
d) P ( - z < Z < z ) = P ( - 0.00 < Z < 0. 00)
CI = 0.9973 % significance level α = 0.0027 % α = 0.000027 α/2 = 0.0000135
z = 0.00003375 ⇒ z = 0.00
NOTE: The value of α is too small. The Empirical Rule establishes that 99.7 % of all values in a normal distribution fall in the interval ( Z ± 3σ)
that means all the values. Then the probability of finding the random variable between that range is close to 1 and we can not find in tables a number to approximate just with only two decimal places
