The <em><u>correct answer</u></em> is:
We can conclude that 68% of the scores were between 55 and 85; 95% of the scores were between 40 and 100; and 99.7% of the scores were between 25 and 100.
Explanation:
The empirical rule tells us that in a normal curve, 68% of data lie within 1 standard deviation of the mean; 95% of data lie within 2 standard deviations of the mean; and 99.7% of data lie within 3 standard deviations of the mean.
The mean is 70 and the standard deviation is 15. This means 1 standard deviation below the mean is 70-15 = 55 and one standard deviation above the mean is 70+15 = 85. 68% of data will fall between these two scores.
2 standard deviations below the mean is 70-15(2) = 40 and two standard deviations above the mean is 70+15(2) = 100. 95% of data will fall between these two scores.
3 standard deviations below the mean is 70-15(3) = 25 and three standard deviations above the mean is 70+15(3) = 115. However, a student cannot score above 100%; this means 99.7% of data fall between 25 and 100.
Find how fast she runs 1 km:
18/2 = 9 minutes.
So we know have K = 9t
Subtract 18 from both sides:
K-18 = 9t -18
Rewrite the right side:
K-18 = 9(t-2)
So 20:4000=1:200
and 50:10000=1:200
reverse
1lb:200ft^2
100ft^2=0.5lb
needs to cover 26400ft^2
100 times 264=26400 so
0.5 lb times 264=132 lb needed for entire yard
Answer:
a. cosθ = ¹/₂[e^jθ + e^(-jθ)] b. sinθ = ¹/₂[e^jθ - e^(-jθ)]
Step-by-step explanation:
a.We know that
e^jθ = cosθ + jsinθ and
e^(-jθ) = cosθ - jsinθ
Adding both equations, we have
e^jθ = cosθ + jsinθ
+
e^(-jθ) = cosθ - jsinθ
e^jθ + e^(-jθ) = cosθ + cosθ + jsinθ - jsinθ
Simplifying, we have
e^jθ + e^(-jθ) = 2cosθ
dividing through by 2 we have
cosθ = ¹/₂[e^jθ + e^(-jθ)]
b. We know that
e^jθ = cosθ + jsinθ and
e^(-jθ) = cosθ - jsinθ
Subtracting both equations, we have
e^jθ = cosθ + jsinθ
-
e^(-jθ) = cosθ - jsinθ
e^jθ + e^(-jθ) = cosθ - cosθ + jsinθ - (-jsinθ)
Simplifying, we have
e^jθ - e^(-jθ) = 2jsinθ
dividing through by 2 we have
sinθ = ¹/₂[e^jθ - e^(-jθ)]
Answer:
Step-by-step explanation:
684 dollars
