Alright
so the first thing you do is set up your equation
it should look something like this:
90=3x+10
next, you subtract 10 from each side resulting in 80
3x=80
divide 80 by three and you should get 26.67 or rounding either 26 or 27
then round up or down... according to the instructions.....
hope I could help! :)) XD
Answer:
B. -4.
Step-by-step explanation:
Answer:

And for this case we can use the complement rule and the normal standard distribution of excel and we got:

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 heights of a population, and for this case we know the distribution for X is given by:
Where
and
And we select a sample size of n =70
From the central limit theorem (n>30)we know that the distribution for the sample mean
is given by:
And we want to find this probability:

And we can use the z score formula given by:

And using this formula we got:

And for this case we can use the complement rule and the normal standard distribution of excel and we got:

67+52+x=180
119+x=180
x=61
hope this helps!
the equation to be used would be x=180-(67+52)