Answer:
The lines DE and BC have the same slope, therefore the two lines, DE and BC, are parallel
Step-by-step explanation:
To prove that DE is parallel to BC, we have;
The slope, m of the lines DE and BC are found from the following equation;
Where;
(x₁, y₁) and (x₂, y₂) = (b, c) and (a + b + c) for DE, we have;
Where we have (x₁, y₁) and (x₂, y₂) = (0, 0) and (2a, 0) for BC, we have;
Therefore, because the lines DE and BC have the same slope, the two lines DE and BC are parallel.
Answer:
0.75
Step-by-step explanation:
The table is not well presented (See Attachment)
There are at least two approaches to this question
Method 1:
Steps
1. Calculate the mean of reported heights
Mean of reported heights = (61+68+57.5+48.5+75+65+80+68+69+63)/10
Mean of reported heights = 655/10
Mean of reported heights = 65.5
2. Calculate the mean of measured heights
Mean of measured heights = (62 + 68 + 56.5 + 47 + 72 + 65 + 78 + 67 + 69.5 + 62.5)/10
Mean of measured heights = 647.5/10
Mean of measured heights = 64.75
3. Get their difference
Difference = Mean of reported heights - Mean of measured heights
Difference = 65.5 - 64.75
Difference = 0,75
Method 2: Calculate the mean of their difference
Mean of difference = Sum of difference / Number of observations
Mean of difference = (-1 + 0 + 1 + 1.5 + 3 + 0 + 2 + 1 – 0.5 + 0.5)/10
Mean of difference = 7.5/10
Mean of difference = 0.75
Note that in both cases, the result is 0,75.
Hence, the reported heights at the school is 0.75 greater than the actual measured height
