Answer:
$12000 should be invested in a fund with a 4% return.
Step-by-step explanation:
Consider the provided information.
An amount of $15,000 is invested in a fund that has a return of 6%.
We need to calculate how much money is invested in a fund with a 4% return if the total return on both investments is $1380.
Let $x should be invested in a fund with a 4% return.
The above information can be written as:
Hence, $12000 should be invested in a fund with a 4% return.
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.