Answer:
n = 1500
Step-by-step explanation:
The sample size is the number of students that were asked
n = 1500
The speed at which Mario can walk is given in the question and it is 3.9 miles/hour. Also we get to know from the question that Mario walked for 0.72 hours. The question requires the answer to the distance for which Mario walked.
Now
Mario in 1 hour can cover a distance of 3.9 miles
The n
The distance covered by Mario in 0.72 hours = (3.9 * 0.72) miles
= 2.808 miles
Then the distance covered by mario in o.72 hours is 2.808 miles.
ANSWER
a=-2, b=3
EXPLANATION
The given equation is

Recall that:

We simplify the left hand side to get:

For this equation to be true, we must have:
-6a=12 and 2+b=5
This implies that,
a=-2 and b=3
Using the laws of logarithms, we get:

The answer is a.
Best is to draw a sketch of the three points.
Next step is to find the distances BC, CD, DB.
The perimeter is the sum of the three distances.
The distances are found using the distance formula:
D=sqrt((y2-y1)^2+(x2-x1)^2)
order of (x1,y1), (x2,y2) is not important.
BC=sqrt((3- -3)^2+(5-3)^2)=sqrt(6^2+2^2)=sqrt(40)=5.324
CD=sqrt((-1-3)^2+(0-5)^2)=sqrt(4^2+5^2)=sqrt(41)=6.403
DB=sqrt((-3- -1)^2+(3-0)^2)=sqrt(2^2+3^2)=sqrt(13)=3.606
So perimeter = BC+CD+DB=16.333 (approximately)