Answer:
And we can find this probability with this difference and using the normal standard distribution
Step-by-step explanation:
Let X the random variable that represent the amount of Jen monthly phone of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And we can use the z score formula given by:
Replacing the info we got:
And we can find this probability with this difference and using the normal standard distribution
Answer:
multiply by 10 on both sides
that is to get rid of the denominator
Idk I have tried and failed miserably
-4r-11=4r+21
Move 4r to the other side
Sign changes from +4r to -4r
-4r-4r-11=4r-4r+21
-4r-4r-11=21
-8r-11=21
Move -11 to the other side
Sign changes from -11 to +11
-8r-11+11=21+11
-8r=21+11
-8r=32
Divide both sides by -8
-8r/-8=32/-8
Answer: r=-4
I know this one give me like 5 minutes