Answer:
the probability that the sample variance exceeds 3.10 is 0.02020 ( 2,02%)
Step-by-step explanation:
since the variance S² of the batch follows a normal distribution , then for a sample n of 20 distributions , then the random variable Z:
Z= S²*(n-1)/σ²
follows a χ² ( chi-squared) distribution with (n-1) degrees of freedom
since
S² > 3.10 , σ²= 1.75 , n= 20
thus
Z > 33.65
then from χ² distribution tables:
P(Z > 33.65) = 0.02020
therefore the probability that the sample variance exceeds 3.10 is 0.02020 ( 2,02%)
The answer is 63.53 subtracts 5.23 from 68.76
Algebra
Use the distributive property to make 5x+5.
5x+5<25
Subtract 5 from both sides.
5x<20
Divide both sides by five.
x<4
Consider the top half of a sphere centered at the origin with radius

, which can be described by the equation

and consider a plane

with

. Call the region between the two surfaces

. The volume of

is given by the triple integral

Converting to polar coordinates will help make this computation easier. Set

Now, the volume can be computed with the integral

You should get