Suppose y varies jointly as x and z. Find y when x = 5 and z = 16, if y = 136 when x = 5 and z = 8. Round your answer to the nearest hundredth, if necessary.

Answer:The value of y when x = 5 and z = 16 is 272Step-by-step explanation:* Lets Talk about the direct variation- y is varies jointly (directly) as x and z, that means there are direct   relation between y , x and z- y increases if x increases or z increases∴ y ∝ x × z- To change this relation to equation we use a constant k∴ y = k (x) (z), where k is the constant of variation- To find the value of k we substitute the values of x , y and z in   the equation above∵ y = 136 when x = 5 and z = 8∴ 136 = k × 5 × 8∴ 136 = 40 k ⇒ divide both sides by 40∴ k = 3.4- Substitute this value in the equation∴ y = 3.4 (x) (z)∵ x = 5 , z = 16∴ y = 3.4 (5) (16) = 272∴ The value of y when x = 5 and z = 16 is 272