Answer:
<u>The correct answer is z = 1.2</u>
Step-by-step explanation:
μ or average income = US$ 3,000
σ or standard deviation = US$ 250
Income in a given month = US$ 3,300
For calculating the z score, we use the following formula:
z = (x – μ) / σ
z = (3,300 – 3,000 / 250)
z = 300/250
z = 6/5 = 1.2
Interpreting z
A Z score tells us how many units of standard deviation (1.2 in this case)from the average a given score is, that is, we do not count in quantity of points, but in quantities of standard deviations. To use the Z score we require the distribution to be normal and to know the average and standard deviation of the scores.
x = 27° (A)
Step-by-step explanation:
5x° + (x + 18)° = 180°
(5x + x)° + 18° = 180°
6x° + 18° = 180°
6x° = 180° - 18°
6x° = 162°
x° = 162 ÷ 6
x° = <u>2</u><u>7</u><u>°</u>
So, the value of x is 27° (A)
<em>Hope </em><em>it </em><em>helpful </em><em>and </em><em>useful </em><em>:</em><em>)</em>
Answer:
The change in the car's distance is 8 feet
Step-by-step explanation:
* Lets explain how to solve the problem
- A car is driving away from a crosswalk
- The distance d (in feet) of the car from the crosswalk t seconds
since the car started moving is given by the formula d = t² + 3.5
- The time increasing from 1 second to 3 seconds
- We need to now the change of the car's distance from the crosswalk
∵ The equation of the distance is d = t² + 3.5
∵ The time is 1 second
∴ d = (1)² + 3.5
∴ d = 1 + 3.5 = 4.5 feet
∵ The time is 3 seconds
∴ d = (3)² + 3.5
∴ d = 9 + 3.5 = 12.5 feet
∵ The change of the distance = d of 3 sec - d of 1 sec
∵ d of 3 sec = 12.5 feet
∵ d of 1 sec = 4.5 feet
∴ The change of the distance = 12.5 - 4.5 = 8 feet
∴ The change in the car's distance is 8 feet
