Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the lifetime for a TV of a population, and for this case we know the distribution for X is given by:
Where 
and 
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability like this:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.
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Answer:
7k
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Step-by-step explanation:
We are trying to combine like terms with the expression: -k - ( - 8k)
We are pretty much solving it.
Solve:
-k - ( - 8k)
The "- ( -" turns into a plus sign.
So it would look like:
-k - -8k or -k + 8k
Now, you would finish solving
-k + 8k = 7k
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Im not sure why you said ur wrong b/c i got the same answer
f(x) = -15+ 7
f(x) = -8
Answer:
The height of rocket is 102.7 meter.
Step-by-step explanation:
Given : Brynn and Denise launch their rockets at the same time.
The height of Brynn’s rocket, in meters, is given by the function 
, where x is the number of seconds after the launch.
The height of Denise’s rocket, in meters, is given by the function
, where x is the number of seconds after the launch.
There is a moment when the rockets are at the same height.
To find : The height
Solution :
When the rockets have same height
So, 
Now, we put x value in any of the function to find height.
, x=1.52
Nearest tenth = 102.7
Therefore, The height of rocket is 102.7 meter.
