Answer:
-1.555 and 1.555
Step-by-step explanation:
For a standard normal distribution:
P(- Ƶ ≤ Z ≤ Ƶ) = 0.88
The normal distribution on the curve is symmetrical about Z = 0
Thus
P( -Ƶ ≤ Z ≤ 0) = P( 0 ≤ Z ≤ Ƶ)
However;
This implies that:
P( -Ƶ ≤ Z ≤ 0) + P( 0 ≤ Z ≤ Ƶ) = 0.88
2P ( 0 ≤ Z ≤ Ƶ) = 0.88
P( 0 ≤ Z ≤ Ƶ) = 0.44
P(Z ≤ Ƶ) - P( Z ≤ 0) = 0.44
Since P(Z ≤ 0) = 0.50
P(Z ≤ Ƶ) = 0.44 + 0.50
P(Z ≤ Ƶ) = 0.94
From the probability value table
z = 1.555
Thus the endpoints are:
-1.555 and 1.555