True or False The point (-2, -1) is a solution to the inequality – y < 0. True False
1 answer:
You might be interested in
Answer: They will charge same amount for 360 minutes of calls.
Step-by-step explanation:
A phone company offers two monthly plans plan A cost $9 Plus And additional 0.12 $ for each minute of calls. Plan B cost $27 plus an additional $0.07 for each minute of calls
For what amount of calling do the two plans cost the same?
Let the each minute of calls be 'x'.
So, for plan A would be
plan A cost $9 Plus And additional 0.12 $ for each minute of calls is expressed as
Plan B cost $27 plus an additional $0.07 for each minute of calls is expressed as
According to question, it becomes,
Hence, they will charge same amount for 360 minutes of calls.
Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the lifetime for a TV 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 the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability like this:
And in order to find these probabilities we can use tables for the normal standard distribution, excel or a calculator.