Umm is this the problem we need to solve?
Answer:
option A
Step-by-step explanation:
given,
10% A grades 80% B grades 10% C grades
This year, managers with scores less than 35 received C's and those with scores above 425 received A's.
The mean has to be middle of two corresponding cutoff value

μ = 230
Cutoff Off C grade corresponds with the area of 0.10 is table A.
corresponding z- score according to Table A
Z = -1.28
now, standard deviation



σ = 152.3
Correct answer is option A
The second option is the right one
Answer:
B. x = -1 ± i
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality<u>
</u>
<u>Algebra I</u>
- Standard Form: ax² + bx + c = 0
- Factoring
- Quadratic Formula:

<u>Algebra II</u>
- Imaginary Numbers: √-1 = i
Step-by-step explanation:
<u>Step 1: Define</u>
x² + 2x = -2
<u>Step 2: Identify Variables</u>
- Rewrite Quadratic in Standard Form [Addition Property of Equality]: x² + 2x + 2 = 0
- Break up Quadratic: a = 1, b = 2, c = 2
<u>Step 3: Solve for </u><em><u>x</u></em>
- Substitute in variables [Quadratic Formula]:

- [√Radical] Evaluate exponents:

- Multiply:

- [√Radical] Subtract:

- [√Radical] Factor:

- [√Radicals] Simplify:

- Factor:

- Divide:
