Answer:
a) (1215, 1297)
b) (1174, 1338)
c) (1133, 1379)
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 1256
Standard Deviation, σ = 41
Empirical Rule:
- Also known as 68-95-99.7 rule.
- It states that almost all the data lies within three standard deviation for a normal data.
- About 68% of data lies within 1 standard deviation of mean.
- About 95% of data lies within two standard deviation of mean.
- About 99.7% of data lies within 3 standard deviation of mean.
a) range of years centered about the mean in which about 68% of the data lies

68% of data will be found between 1215 years and 1297 years.
b) range of years centered about the mean in which about 95% of the data lies

95% of data will be found between 1174 years and 1338 years.
c) range of years centered about the mean in which about all of the data lies

All of data will be found between 1133 years and 1379 years.
<em>Answer</em><em>:</em>
<h2>
<em>2</em><em>0</em><em> </em><em>years</em><em> </em><em>old</em><em>.</em></h2>
<em>Sol</em><em>ution</em><em>,</em>
<em>Let</em><em> </em><em>the</em><em> </em><em>age</em><em> </em><em>of</em><em> </em><em>sister</em><em> </em><em>be</em><em> </em><em>X</em>
<em>Let</em><em> </em><em>the</em><em> </em><em>age</em><em> </em><em>of</em><em> </em><em>boy</em><em> </em><em>be </em><em>2</em><em>x</em>
<em>Now</em><em>,</em>
<em>Five</em><em> </em><em>years</em><em> </em><em>ago</em><em>,</em>
<em>
</em>
<em>Again</em><em>,</em>
<em>Repla</em><em>cing</em><em> </em><em>value</em><em>,</em>
<em>
</em>
<em>hope</em><em> </em><em>this</em><em> </em><em>helps</em><em>.</em><em>.</em>
<em>Good</em><em> </em><em>luck</em><em> on</em><em> your</em><em> assignment</em><em>.</em><em>.</em>
Let's make the width 'x'.
And the length 'x+4'.
Perimeter is adding up ALL the sides.
Add: x + x + 4 + x + x + 4.
Simplify:
x + x + 4 + x + x + 4 = 4x + 8
The independent variable is the days he spends reading because nothing we have can determine that. However the dependent variable is the total minutes of reading because it relies on the independent variable to figure out. You can't find the total minutes without knowing the days he spends. The equation sould be d times the amount he reads per day =m