Math Is Fun Forum

Can someone explain how I go about the following...

Q. a large number of bricks were found to have a MEAN compresive strength of 36.24N/mm2, with a standard deviation of               1.38 N/mm2 .

1 I need to find within what limits the compressive strength  of the samples could be expected to lie.

2.the probability that a random brick would have a compressive strength less than 37.62N/mm2

3. the probability that a random brick would have a compressive stength more than 33.48N/mm2

4.the probability that a random brick would have a compressive strength between 34.86 N/mm2 and 39.00N/mm2

Thanks....Mark

Hi,

Can someone show me how to solve this cubic equation

h3 + 87.48h - 305.73 = 0

Change the figures please so I can work it out myself,just want a step by step example

Thanks Mark

Can someone show me how to transpose this in terms of h

s = pi r (r + 2h)

Thanks...Mark

Hi,

I know how to find the volume of a sphere when height and radius is given but how do I go about calculating the height of a sphere cap if only the volume and radius of sphere cap are given? I know its a cubic equation but dont know how to do this.

Thanks....Mark

r = 5.4  V=160 in this instance