Answer:
$301 - $397
Step-by-step explanation:
Using the Empirical rule
1) 68% of data falls within 1 standard deviation from the mean - that means between μ - σ and μ + σ .
2)95% of data falls within 2 standard deviations from the mean - between μ – 2σ and μ + 2σ .
3)99.7% of data falls within 3 standard deviations from the mean - between μ - 3σ and μ + 3σ .
From the above question,
Mean = 349 , standard deviation = 24.
Confidence interval = 95%
Using 2)95% of data falls within 2 standard deviations from the mean - between μ – 2σ and μ + 2σ .
μ – 2σ
= 349 - 2(24)
= 349 - 48
= 301
μ + 2σ
349 + 2(24)
= 349 + 48
= 397
Therefore, according to the standard deviation rule, approximately 95% of the students spent between $301 and $397 on textbooks in a semester.
Answer:
see below
Step-by-step explanation:
Clearly, if you turn the figure sideways or upside down (rotate 90° or 180°), you do not have the same figure. It has no rotational symmetry.
However, if you reverse it left-to-right, you get exactly the same figure. So, it has line symmetry about a vertical center line.
6x+1 / 2x +6 - 5/2
Factor 2 out of the denominator of the first fraction:
6x+1 / 2(x+3) - 5/2
Rewrite 5/2 to have a common denominator with the first fraction:
6x+1/2(x+3) - 5(x+3) / 2(x+3)
Simplify terms:
6x +1 - 5(x+3) / 2(x+3)
Use distributive property:
6x +1 - 5x -15 / 2(x+3)
Combine like terms for final answer:
(x-14) / 2(x+3)
Answer: 2014
Step-by-step explanation:
LED: -25x + 6y = 20
CFL: 15x + 2y = 322
we need to find which year it was the same to know where LED lighting surpassed CFL lighting
-25x + 6y = 20
15x + 2y = 322 (-3)
-25x + 6y = 20
<u>-45x - 6y = -966 </u>
-70x = -946
x = 13.51
The nearest year would be 14 which is 2014
