Answer:
0.0143 = 1.43% probability that first 4 digits of the code are even numbers.
Step-by-step explanation:
Arrangements of n elements:
The number of possible arrangements of n elements is given by:

Probability:
A probability is the number of desired outcomes divided by the number of total outcomes.
In this question:
Desired outcomes:
First four digits are even(2, 4, 6 and 8 are even, so arrangements of 4 elements).
Last four digits are odd(1, 3, 5 and 7 are odd, so the last four elements are also arrangements of 4 elements). So

Total outcomes:
Arrangements of 8 digits. So

Probability:

0.0143 = 1.43% probability that first 4 digits of the code are even numbers.
Answer:
The measure of the exterior angle is 92 degrees
Step-by-step explanation:
Problem 16)
we know that
An exterior angle of a triangle is equal to the sum of the opposite interior angles
so
In this problem

solve for x


Find the measure of the exterior angle

Answer:
The probability that the next failure will not occur before 30 months have elapsed is 0.0454
Step-by-step explanation:
Using Poisson distribution where
t= number of units of time
x= number of occurrences in t units of time
λ= average number of occurrences per unit of time
P(x;λt) = e raise to power (-λt) multiplied by λtˣ divided by x!
here λt = 25
x= 30
P(x= 30) = 25³⁰e⁻²⁵/ 30!
P (x= 30) = 8.67 E41 * 1.3887 E-11/30! (where E= exponent)
P (x=30) = 1.204 E31/30!
Solving it with a statistical calculator would give
P (x=30) = 0.0454
The probability that the next failure will not occur before 30 months have elapsed is 0.0454