Answer:
Step-by-step explanation:
Area of garden = length * breadth = 90 * 75 = 6750 Sq . m
= 6750 / 1000 = 0.675 hectare
Area of path = 100 * 85 - 90 * 75
= 8500 - 6750 = 1750 Sq. m
Variance is the average of the square of the differences of each data with the mean. To calculate for the variance, we first calculate for the mean. Then, we subtract each data with the mean. Next, each difference would be squared and added. The resulting value would be divided on how many data are used. We calculate as follows:
Mean = <span>9 + 7 + 6.5 </span>+ 7.5 + 7 + 8 + 5 + 6 + 7.5 + 8 / 10
Mean = 6.4
Squared of the sum of the differences = (9-6.4)^2 + (7-6.4)^2 + (6.5-6.4)^2 + (7.5-6.4)^2 + (7-6.4)^2 + (8-6.4)^2 + (5-6.4)^2 + (6-6.4)^2 + (7.5-6.4)^2 + (8-6.4)^2 = 17.15
Variance = 17.15 / 10 = 1.715
Since vertical angles are congruent, (4x+7)=5(x-4). So simplifying we get 4x+7=5x-20. If we add 20 on both sides we get 4x+27=5x. Now when we subtract x from both sides, we get x=27
