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Answer: C) 81.5%</h3>
This value is approximate.
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Explanation:
We have a normal distribution with these parameters
- mu = 128 = population mean
- sigma = 30 = population standard deviation
The goal is to find the area under the curve from x = 68 to x = 158, where x is the number of text messages sent per day. So effectively, we want to find P(68 < x < 158).
Let's convert the score x = 68 to its corresponding z score
z = (x-mu)/sigma
z = (68-128)/30
z = -60/30
z = -2
This tells us that the score x = 68 is exactly two standard deviations below the mean mu = 128.
Repeat for x = 158
z = (x-mu)/sigma
z = (158-128)/30
z = 30/30
z = 1
This value is exactly one standard deviation above the mean
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The problem of finding P(68 < x < 158) can be rephrased into P(-2 < z < 1)
We do this because we can then use the Empirical rule as shown in the diagram below.
We'll focus on the regions between z = -2 and z = 1. This consists of the blue 13.5% on the left, and the two pink 34% portions. So we will say 13.5% + 34% + 34% = 81.5%
Approximately 81.5% of the the population sends between 68 and 158 text messages per day. This value is approximate because the percentages listed in the Empirical rule below are approximate.
THE CORRECT ANSWER IS THE LAWS OF THERMODYNAMICS. HOPE THIS HELPS!!!!
Years of decay...
It takes around 4 years for something to go through their half life (depending on the thing). This chart is showing the years go by (half lives that occur within the years) while the decaying is happening.
Answer:
Total cost of the grill installment plan = 2290
Step-by-step explanation:
370 + 1920 = 2290
Answer:
a=6
b=5.5
Step-by-step explanation:
not very sure but..
since 8X2=16,
a=3X2
b=11/2