a energy stored in the spring is directly proportional to the square of its extension. When a spring is stretched by d cm, the energy stored in it is E joules (J). If the extension of the spring is decreased by 25 %, find the percentage decrease in the energy stored. ​

Prove that 3: 8 is equivalent to 12: 32.a. use diagrams to support your answer.

Three cylinders have a volume of 2836 cm^3. cylinder a has a height of 900 cm. cylinder b has a height of 225 cm. cylinder c has a height of 100 cm. find the radius of each cylinder. use 3.14 as an approximate for π

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.