Evaluate the expression. (-1/2)^2 need two answers for crown

4. The annual salaries of employees in a large company are approximately

svetoff [14.1K]

a. What percent of people earn less than $40000?

Solution: Let S be the random variable of a salary of employee (in $), S ~ N(50000,20000). Then the random

variable X =−50000

20000

~N(0,1).

( < 40000) = ( <

40000 − 50000

20000 ) = ( < −0.5) = (−0.5) = 0.3085375.

Here Φ(x) denotes the cumulative distribution function of a standard normal distribution.

Answer: 31%.

b. What percent of people earn between $45000 and $65000?

Solution:

(45000 < < 65000) = (

45000 − 50000

20000 < <

65000 − 50000

20000 ) = (−0.25 < < 0.75)

= (0.75) − (−0.25) = 0.7733726 − 0.4012937 = 0.3720789.

Answer: 37%.

c. What percent of people earn more than $70000?

Solution:

( > 70000) = ( >

70000 − 50000

20000 ) = ( > 1) = 0.8413447.

Answer: 84%.

5 0

2 years ago

Use the power-reducing formulas to rewrite the expression as an equivalent expression that does not contain powers of trigonome

ratelena [41]

Answer:

$x = 0.175\cdot (1-\cos 4\cdot \theta)$

Step-by-step explanation:

Let use the following trigonometric identities:

$\sin^{2}\theta = \frac{1-\cos 2\cdot \theta}{2} \\\cos^{2}\theta = \frac{1+\cos 2\cdot \theta}{2}$

Then, the equation is simplified by substituting its components:

$x = 1.40\cdot \left(\frac{1-\cos 2\cdot \theta}{2} \right)\cdot \left(\frac{1+\cos 2\cdot \theta}{2} \right)$

$x = 0.35\cdot (1-\cos^{2}2\cdot \theta)$

$x = 0.35\cdot \sin^{2}2\cdot \theta$

$x = 0.35\cdot \left(\frac{1-\cos 4\cdot \theta}{2} \right)$

$x = 0.175\cdot (1-\cos 4\cdot \theta)$

7 0

3 years ago

Read 2 more answers

A mother is 1 and 3/4 times as tall as her son. Her son is 3 feet tall. How tall is the mother?

Inga [223]

Answer:

The mom is 5 feet 3 inches

Step-by-step explanation:

Step 1: Make an equation

m = 1 3/4 * 3

Step 2: Solve

m = (4/4+3/4) * 3

m = 7/4 * 3

m = 21/4

m = 5.25

m = 5 feet 3 inches

Answer: The mom is 5 feet 3 inches

7 0

3 years ago

Read 2 more answers

Will award brainliest to correct answer!

Artyom0805 [142]

Let's begin noting that a triangle is isosceles if and only if two of its angles are congruent. We can thus find the angle <ABP, recalling that the sum of the interior angles of a triangle is equal to 180°.

$\angle \: ABP = \frac{180 - 80}{2} = 50 \degree$

Finally, let point K be the intersection between segments BC and PQ, and let's note that the triangle PQB is a right isosceles triangle, since all the angles in a square are equal to 90°, and the two triangles APB and BQC are congruent.

Therefore, the angle BKQ is equal to 180-50-45=85°.

Of course angle BKP=180-85=95°.

Hope this helps :)

6 0

2 years ago

Can someone help me with this question?

Lina20 [59]

Answer:1/3

Step-by-step explanation:

gradient equals

$\frac{Y2-Y1}{X2-X1}$