Considering the angle a by cosine rule
11^2 =7 ^2 +15^2 - 2(7)(15)cos(a)
When you do the maths,
Cos(a) =153/210 =0.729
a= cos inverse of 0.729
a=43 degrees
Considering angle b
7^2=15^2 +11^2 -2(11)(15) cos(b)
This will result in cos(b) =297/330=0.9
b= cos inverse of 0.9 = 25.8 degrees
Considering angle c
15^2=7^2 +11^2 - 2(11)(7) cos(c)
Cos(c) will be = -55/154 = -0.357
c= cos inverse of -0.357=110.9
Comparing the angles a,b and c,
C is the largest size in the triangle with an angle of 110.9 degrees
Am I right please ??
120 students are in the 7th grade.
We can use the coordinates (-4, 5) and (0, 6) to find the slope.
Slope Formula: 
Solve: 
The slope of the line is \Large\boxed{\mathsf{1/4}}
Written in slope-intercept form: y = 1/4x + 6
Hope This Helped! Good Luck!
Answer:
Last equation given in the list of possible answers:
5 ( 1.5 + 1.5 + x ) = 25
Step-by-step explanation:
We need to include in the total addition of miles ridden during the week:
a) 1.5 miles to the school
b) 1.5 miles from school back home
c) x miles for the evening ride
so for the miles ridden per day we have: "1.5 +1.5 + x"
Now, since per week she does 5 days like this, then we need to multiply the expression above by 5 in order to total the number of miles she rides weekly (25 miles)
5 ( 1.5 + 1.5 + x ) = 25
And we can use this equation to find the amount "x" that Rin rides in the evening.
Answer and Explanation:
Given : The random variable x has the following probability distribution.
To find :
a. Is this probability distribution valid? Explain and list the requirements for a valid probability distribution.
b. Calculate the expected value of x.
c. Calculate the variance of x.
d. Calculate the standard deviation of x.
Solution :
First we create the table as per requirements,
x P(x) xP(x) x² x²P(x)
0 0.25 0 0 0
1 0.20 0.20 1 0.20
2 0.15 0.3 4 0.6
3 0.30 0.9 9 2.7
4 0.10 0.4 16 1.6
∑P(x)=1 ∑xP(x)=1.8 ∑x²P(x)=5.1
a) To determine that table shows a probability distribution we add up all five probabilities if the sum is 1 then it is a valid distribution.


Yes it is a probability distribution.
b) The expected value of x is defined as

c) The variance of x is defined as

d) The standard deviation of x is defined as


