Answer:
y = -3x -1
Step-by-step explanation:
the slope is -3 and the y-intercept is -1
Answer:
x equals plus or minus square root of 5 minus 1
Step-by-step explanation:
we have

Divide by 2 the coefficient of the x-term

squared the number

Adds both sides


Rewrite as perfect squares

take the square root both sides


therefore
x equals plus or minus square root of 5 minus 1
Answer:
a)
b) 
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".
Part a
Let X the random variable that represent the weights 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 find tables for the normal standard distribution, excel or a calculator.
Part b
For this case we select a sample size of n =32. Since the distribution for X is normal then the distribution for the sample mean
is given by:
And the new z score would be:



Answer:

Step-by-step explanation:
I am going to say that:
Mary's amount is x.
Ashley's amount is y.
Oscar's amount is z.
Mary has at least 3 times the amount of cash that ashley and oscar have combined
Ashley's and Oscar's combined amount is y + z.
3 times this amount is 3(y + z).
At least 3 times means that z is equal or greater than 3(y + z).
So
