Answer:
15.6
Step-by-step explanation:
First, multiply the midpoint of each class by its frequency, as follows:
Class midpoint frequency midpoint*frequency
0-9 4.5 24 4.5*24 = 108
10-19 14.5 20 14.5*20 = 290
20-29 24.5 32 24.5*32 = 784
Total 76 1182
The mean is computed as the division between the addition of the "midpoint*frequency" column by the addition of "frequency" column.
mean = 1182/76 ≈ 15.6
We are given:
- Parallelogram CDEF
- ∠C = 13x - 10
- ∠D = 5x + 10
To Find: ∠E
Concept Used:
- Adjacent angles of a Parallelogram are Supplementary
Finding the value of 'x':
Since adjacent angles of a parallelogram are Supplementary:
∠D + ∠C = 180
5x + 10 + 13x - 10 = 180 [replacing the values of angle C and D]
18x = 180
x = 10 [dividing both sides by 18]
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Finding Measure of Angle D:
We are given that:
∠D = 5x + 10
∠D = 5(10) + 10 [since x = 10]
∠D = 60°
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Finding the measure of ∠E:
∠D and ∠E are Adjacent angles
Since Adjacent angles are Supplementary:
∠D + ∠E = 180
60 + ∠E = 180
∠E = 120° [subtracting 60 from both sides]
Hence, the measure of ∠E = 120°
P ( A ) = 0.45 - probability that the land has oil,
P ( B ) = 0.8 - probability that the test predicts it
P ( A ∩ B ) = P ( A ) · P ( B ) = 0.45 · 0.8 = 0.36
Answer: The probability that the land has oil and the test predicts it is 36 %.
