Answer/Step-by-step explanation:
Area of trapezium = ½*(AD + BC)*AB
Area = 42 cm²
AD = (x + 8) cm
BC = (x + 5) cm
AB = x cm
Plug in the values into the equation
42 = ½((x + 8) + (x + 5))*x
42 = ½((x + 8 + x + 5)*x
42 = ½(2x + 13)*x
Multiply both sides by 2
42*2 = (2x + 13)*x
84 = 2x² + 13x
2x² + 13x = 84
Subtract both sides by 84
2x² + 13x - 84 = 0
Answer:
Slope= y=1/2x+6
Step-by-step explanation:
Hope it helps.
Answer:
A = 201.06 square inches
Step-by-step explanation:
Radius of the pizza is 8 inches.
It is required to find the area of the pizza get by Emily's family.
Pizza is in the shape of circle. Area of a circular figure is given by :
So, the Emily's family will get 201.06 square inches of pizza.
Let's call our estimate x. It will be the average of n IQ scores. Our average won't usually exactly equal the mean 97. But if we repeated averages over different sets of tests, the mean of our estimate the average would be the same as the mean of a single test,
μ = 97
Variances add, so the standard deviations add in quadrature, like the Pythagorean Theorem in n dimensions. This means the standard deviation of the average x is
σ = 17/√n
We want to be 95% certain
97 - 5 ≤ x ≤ 97 + 5
By the 68-95-99.7 rule, 95% certain means within two standard deviations. That means we're 95% sure that
μ - 2σ ≤ x ≤ μ + 2σ
Comparing to what we want, that's means we have to solve
2σ = 5
2 (17/√n) = 5
√n = 2 (17/5)
n = (34/5)² = 46.24
We better round up.
Answer: We need a sample size of 47 to be 95% certain of being within 5 points of the mean
The distance between these points are 6
