Answer: 0.8238
Step-by-step explanation:
Given : Scores on a certain intelligence test for children between ages 13 and 15 years are approximately normally distributed with 
and 
.
Let x denotes the scores on a certain intelligence test for children between ages 13 and 15 years.
Then, the proportion of children aged 13 to 15 years old have scores on this test above 92 will be :-
![P(x>92)=1-P(x\leq92)\\\\=1-P(\dfrac{x-\mu}{\sigma}\leq\dfrac{92-106}{15})\\\\=1-P(z\leq })\\\\=1-P(z\leq-0.93)=1-(1-P(z\leq0.93))\ \ [\because\ P(Z\leq -z)=1-P(Z\leq z)]\\\\=P(z\leq0.93)=0.8238\ \ [\text{By using z-value table.}]](https://tex.z-dn.net/?f=P%28x%3E92%29%3D1-P%28x%5Cleq92%29%5C%5C%5C%5C%3D1-P%28%5Cdfrac%7Bx-%5Cmu%7D%7B%5Csigma%7D%5Cleq%5Cdfrac%7B92-106%7D%7B15%7D%29%5C%5C%5C%5C%3D1-P%28z%5Cleq%20%7D%29%5C%5C%5C%5C%3D1-P%28z%5Cleq-0.93%29%3D1-%281-P%28z%5Cleq0.93%29%29%5C%20%5C%20%5B%5Cbecause%5C%20P%28Z%5Cleq%20-z%29%3D1-P%28Z%5Cleq%20z%29%5D%5C%5C%5C%5C%3DP%28z%5Cleq0.93%29%3D0.8238%5C%20%5C%20%5B%5Ctext%7BBy%20using%20z-value%20table.%7D%5D)
Hence, the proportion of children aged 13 to 15 years old have scores on this test above 92 = 0.8238
Answer:
(-(7-9))(z)-6z= 8(-6+2)
Simplify
-(-2)(z) -6z =8(-6+2)
Multiply 8*-6 and 8*2
2z -6z= -48+16
Combine like terms
2z+-6z =-32
-4z=-32
Divide both sides by -4
z=8
Step-by-step explanation:
Answer:
f(-2) = 54
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Algebra I</u>
Step-by-step explanation:
<u>Step 1: Define</u>
f(x) = 3x(x² + 4x - 5)
f(-2) is x = -2
<u>Step 2: Evaluate</u>
- Substitute in <em>x </em>[Function]: f(-2) = 3(-2)[(-2)² + 4(-2) - 5]
- [Brackets] Evaluate exponents: f(-2) = 3(-2)[4 + 4(-2) - 5]
- [Brackets] Multiply: f(-2) = 3(-2)[4 - 8 - 5]
- [Brackets] Subtract: f(-2) = 3(-2)[-4 - 5]
- [Brackets] Subtract: f(-2) = 3(-2)(-9)
- Multiply: f(-2) = -6(-9)
- Multiply: f(-2) = 54
A) 20.9
b) (230 + x) / 12 = 22
230 + x = 264
x = 34 years old
