Answer:
Step-by-step explanation:
hello :
x² - 6x = 7
x² - 6x+9-9___= 7
(x - 3 )²= __16_
x - 3= +/-_4__
x-3=4__and x-3 =_-4_
Answer:
99.7%
Step-by-step explanation:
Given that mean (μ) = 394.3 ms and standard deviation (σ) = 84.6 ms.
The empirical rule states that for a normal distribution:
- 68% falls within one standard deviation (μ ± σ)
- 95% falls within two standard deviation (μ ± 2σ)
- 99.7% falls within three standard deviation (μ ± 3σ)
one standard deviation = 394.3 ± 84.6 = (309.7, 478.9). 68% falls within 309.7 and 478.9 ms
two standard deviation = 394.3 ± 2 × 84.6 = (225.1, 563.5). 95% falls within 225.1 and 563.5 ms
three standard deviation = 394.3 ± 3 × 84.6 = (140.5, 648.1). 99.7% falls within 140.5 and 648.1 ms
<span>Chris' average speed is 3.5mph:
Lets take Chris' brother speed = B
then Chris speed = (B+ 1) mph-------given in the question
and:
The average speed for covering 18 miles= chris' average speed + his brother's
average speed = (B+ 1) + B
since Speed = Distance covered / time taken
then average speed for 18 miles can also be found by: 18 miles/3 hours = 6 miles per hour
then we have; (B+ 1) + B = 6mph
(B +1) = (6-B)
B+B = 6-1=5
2B=5
B=5/2=2.5 mph (this is Chris' brother average speed)
Hence Chris' average speed is = B+1= 2.5+1= 3.5mph</span>
Can you re order them I don’t understand your problems
