Answer:
48 years old
Step-by-step explanation:
Let x = Mikhail's age
then x-15 = Gabrielle's age
x + x-15 = 81
2x-15 = 81
2x = 96
x = 48 years old
Answer:
a) The 90% confidence interval is 
b) The margin of error is 0.063.
Step-by-step explanation:
We have to construct a 90% confidence interval for the proportion of students enrolled in college or a trade school within 12 months of graduating from high school in 2013.
We have a sample of 160 students, and a proportion of:
The standard deviation is:
As the sample size is big enough, we use the z-value as statistic. For a 90% CI, the z-value is z=1.645.
Then, the margin of error is:
Then, the 90% confidence interval is:
Answer:
(-1, -8)
Step-by-step explanation:
So you would do the simplifying by "subtracting" the equations from each other. So to isolate the x, you could subtract the y away.
8x + y = -16
-3x + y = -5
-___________
11x = -11
x = -1
Then, substitute x into either equation.
8(-1) + y = -16
-8 + y = -16
Isolate y.
y = -8
Answer:
It started on the 55th floor.
Step-by-step explanation:
We can work backwards from the 54th floor. Since we are working <em>backwards</em>, if the elevator goes up, we will subtract and if it goes down, we will add. Starting with 54, we get 54 + 5 = 59, then 59 - 9 = 50, then 50 + 2 = 52, then 52 - 6 = 48, then 48 + 14 = 62, then 62 - 7 = 55.
Answer:
y=-2x+18
Step-by-step explanation:
so, we use the format y=mx+b where m and b are numbers. b=18, and m=-2, since he SPENDS 2 dollars each day. y=-2x+18 would be your answer. remember, b is also the y intercept, so one of the points that would work would be (0, 18) and the x intercept would be when y is zero, aka 0=-2x+18 which we can solve to get (9,0)
