4x² - 100 = 0
<u> + 100 + 100</u>
<u> 4x²</u> = <u>100</u>
4 4
x² = 25
x = <u>+</u>5
4(5)² - 100 = 0
4(25) - 100 = 0
100 - 100 = 0
0 = 0
4(-5)² - 100 = 0
4(25) - 100 = 0
100 - 100 = 0
0 = 0
The roots of the equation is positive or negative 5.
Answer:
67.75%
Step-by-step explanation:
Given:
Given that:
µ = 76 ; σ = 4.7
P(x < 80.7) - P(x < 71.4)
Obtain the standardized score, Z ; x = 71. 4
Zscore = (x - μ) / σ
P(x < 71.4) = (71.4 - 76) / 4.7
P(x < 71.4) = - 4.6 / 4.7
P(x < 71.4) = - 0.9787
P(z < 0.9787) = 0.16386
x = 80.7
P(x < 80.7) = (80.7 - 76) / 4.7
P(x < 80.7) = 4.7 / 4.7
P(x < 80.7) = 1
P(z < 1) = 0.84134
0.84134 - 0.16386 = 0.67748 = 67.748% = 67.75%
