To calculate Mean: add up all the numbers ⇒ 3+5+8+k+14+17 = 47 + k then divide by how many numbers there are ⇒ 6 The Mean is already given as 11 11 = (47 + k) / 6 Cross multiply to solve for k : k = (6 X 11) - 47 k = 19

From the kip of a storey-buliding, the angle of depression of a mango on a tree 20 m away from the base of the storey-building is 68°. if the mango is 4.5 m above the ground, what is the height of the storey-building to the nearest metre?