First question: 0
Second question: 0.94
Answer:
The probability that the diameter falls in the interval from 2499 psi to 2510 psi is 0.00798.
Step-by-step explanation:
Let's define the random variable,
"Comprehensive strength of concrete". We have information that
is normally distributed with a mean of 2500 psi and a standard deviation of 50 psi (or a variance of 2500 psi). In other words,
.
We want to know the probability of the mean of X or
that falls in the interval
. From inference theory we know that :

Now we can find the probability as follows:

Where
, then:

They need to have common denomenators so change the fractions to 12/15 - 5/15 which is 7/15.
Answer is 4/7
You divide the length of C'D' over the length of CD
C'D'/CD = 8/14 = 4/7
The scale factor is smaller than 1, so C'D' is shorter than CD
dot on top of earth = plane position at the time of observation (right one when 37°, left one 53°)
then the geometry is zoomed on the left side