Answer:
Width= 120 ft
Length= 285 ft
Step-by-step explanation:
W= width and (3w-75)= length since it's 75 less than 3 times the width
w+w+(3w-75)+(3w-75)=810
8w-150=810
8w=960
w=120
So the width is 120 ft
Then substitute the 120 in for w in the length
L= 3(120)-75
L=360-75
L=285
So the length is 285 ft
You can check because 120+120+285+285=810, and because 120×3-75=285!
Answer:
Mean = 35
Variance = 291.7
Step-by-step explanation:
Data provided in the question:
X : 1, 2, 3, 4, 5, 6
All the data are independent
Thus,
The mean for this case will be given as:
Mean, E[X] = 
or
E[X] = 
or
E[X] = 3.5
For 10 days, Mean = 3.5 × 10 = 35
And,
variance = E[X²] - ( E[X] )²
Now, for this case of independent value,
E[X²] = 
or
E[X²] = 
or
E[X²] = 
or
E[X²] = 15.167
Therefore,
variance = E[X²] - ( E[X] )²
or
variance = 15.167 - 3.5²
or
Variance = 2.917
For 10 days = Variance × Days²
= 2.917 × 10²
= 291.7
The value of the expression 5x – 2y + (7x – y) when x = 7 and y = -2 is 90
<h3>How to evaluate the expression?</h3>
The expression is given as:
5x – 2y + (7x – y)
Substitute x = 7 and y = –2 in the above expression
5 * 7 - 2 * -2 + (7 * 7 + 2)
Evaluate the expression
90
Hence, the value of the expression 5x – 2y + (7x – y) when x = 7 and y = -2 is 90
Read more about expressions at:
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Answer:
.
It means that 673 of 9 inch tiles are required to cover an area of 400 square feet, when spacing the tiles a quarter inch apart.
Step-by-step explanation:
Given:
The function relating number of 9 inch tiles required and area to cover is:

Now, plug in 400 for
to evaluate
.

Therefore, Don required 673 of 9 inch tiles to cover an area of 400 square feet, when spacing the tiles a quarter inch apart.