Answer: $85,000
Step-by-step explanation:
Given : In a given population of two-earner male-female couples, male earnings have a mean of $40,000 per year and a standard deviation of $12,000.

Female earnings have a mean of $45,000 per year and a standard deviation of $18,000.

If C denote the combined earnings for a randomly selected couple.
Then, the mean of C will be :-

Hence, the mean of C = $85,000
Answer:
Surface area of cube = 6x²
surface area of cube = surface area of sphere
it means that 6x²=4πr²
x²=





Answer:
<em><u>The answer here is 3/25, more left handed students.</u></em>
Step-by-step explanation:
12/100 are left handed, which reduces to 3/25. This means that there are only 3 left handed kids for every 22 right handed kids, showing that there are more right handed students than left handed.
Answer:
Lins house is 315 metres from school
Step-by-step explanation:
It's simple, just do 450-135.
Explanation:
When the points are plotted on a graph, it is easy to see that the slope of AC is -2 and the slope of BC is 1/2. These slope values have a product of -1, so the corresponding line segments are perpendicular to each other.
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If you have studied vectors, you can find the dot product of AC with BC:
AC = (-5, 3) -(-2, -3) = (-3, 6)
BC = (6, 1) -(-2, -3) = (8, 4)
The dot product is ...
(-3, 6)·(8, 4) = (-3)(8) + (6)(4) = -24+24 = 0
When the dot product of vectors is zero, they are perpendicular.