First you chang top fractions into decimal add and divide that by 4 which is equal to 0.375 hope it helps.
7.44-6.26=1.18
1.18 in minutes is 78 minutes bc 1 hour is 60 minutes + 18 minutes is 78
Hope this helps :D
Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.
If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:
E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]
Or, if you're given the expectation and variance of <em>X</em>, you have
Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²
→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]
Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.
Answer:
A
Step-by-step explanation:
Answer:
304(pi) g
Step-by-step explanation:
First we find the volume of the hollow ball. Then we find the mass using the volume and density.
Let R = exterior radius = 3 cm
Let r = interior radius = 2 cm
volume = exterior volume - interior volume
volume = (4/3)(pi)R^3 - (4/3)(pi)r^3
volume = (4/3)(pi)(R^3 - r^3)
volume = (4/3)(pi)(3^3 - 2^3) cm^3
volume = (4/3)(pi)(27 - 8) cm^3
volume = (76/3)pi cm^3
Now we use the density and the volume to find the mass.
density = mass/volume
mass = density * volume
mass = 12 g/cm^3 * (76/3)pi cm^3
mass = 304(pi) g
Answer: 304(pi) g
