When 440 junior college students were surveyed, 200 said they have a passport. Construct a 95% confidence interval for the propo
1 answer:
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Answer:
Area = 370 m²
Cost to paint = £105
Step-by-step explanation:
Area of the wall of a cinema hall = Area of a trapezoid (1)+ Area of a rectangle (2) + Area of a trapezoid (3)
Area of a trapezoid =
where and
are the parallel sides and h is the distance between these sides.
Area of trapezoid (1) =
= 69 m²
Area of the rectangle (2) = Length × Width
= 12 × 15
= 180 m²
Area of the trapezoid (3) =
= 121 m²
Now area of the wall = 69 + 180 + 121
= 370 m²
One tin covers the area = 25 m²
Number of tins required to paint the wall =
=
= 14.8
Therefore, number of tins to be purchased = 15
Cost to paint the complete wall = 15 × £7
= £105
Answer:
Rate of change of the area of the square is 42 units at t = 2.
Step-by-step explanation:
We note that the area of the square is given by: but we aim to find
. But we can use the chain rule to pull out that dA/dt. Doing so gives us:
Now, (by the power rule and
But since we have "x" and not "t", we want to find what x is when t = 2. Substituting t = 2 gives us x(2) = 3(2) + 1 = 7.
So, finally, we see that: