A score of 85 would be 1 standard deviation from the mean, 74. Using the 68-95-99.7 rule, we know that 68% of normally distributed data falls within 1 standard deviation of the mean. This means that 100%-68% = 32% of the data is either higher or lower. 32/2 = 16% of the data will be higher than 1 standard deviation from the mean and 16% of the data will be lower than 1 standard deviation from the mean. This means that 16% of the graduating seniors should have a score above 85%.
Answer:
<em>angle ABD =</em><u><em>55 degree</em></u>
<em>angle BCD= </em><u><em>125 degree</em></u>
Step-by-step explanation:
angle ABD and angle DBC are supplementary angles.
Hence, angle ABD +angle DBC = 180 --equation 1
angle ABD = (2x+15) ---equation 2
angle BCD = (4x+45) ------equation 3
ABD+DBC=180
(2x+15) + ( 4x+45 ) = 180
2x+4x+15+45=180
6x+60=180
6x=180-60
6x=120
x=120/6=20
angle ABD= 2x+15= 2(20) +15
=40+15= 55 degree
angle BCD= 4x+45 = 4(20) +45
= 80+45= 125 degree
Hence, angle ABD =55 degree
angle BCD= 125 degree
<em>Hope this helps.</em>
Answer:
The numbers in the second row of each collumn is increasing by 4 every time the numbers in the first row increase by 1.
Q) Without a calculator, we must estimate the value of the following expression:
![3-\sqrt[]{38}.](https://tex.z-dn.net/?f=3-%5Csqrt%5B%5D%7B38%7D.)
A) I estimate 3 - √38 to be approximately -3.2.
First, we estimate the value of √38. √38 is between √36 and √49, but close to √36 (since 38 is closer to 4 than it is to 9). Since √36 is 6, √38 is probably something like 6.1 or 6.2. Filling 6.2 in the expression and simplifying, we have this:

So, I expect the number 3 - √38 to be close to -3.2.
Using a calculator we find that: 3 - √38 ≅ -3.16, which it is approximately the result that we found.
Answer
Without a calculator we find that 3 - √38 ≅ -3.2.
It contains one significant digit and the rule for this one is that leading zeros in fractions less than one are not significant.