Answer:
the cost of brand x dog food is $2
Step-by-step explanation:
Let brand X dog food be represented as A
Let Brand Y dog food be represented as B
3 bags of Brand X dog food and 4 bags of Brand Y dog food costs $18,
3A+4B=18
4 bags of Brand X dog food and 3 bags of Brand Y dog food costs
$17.
4A+3B= 17
Using Elimination method
Multiply
- 3A+4B=18 by coefficient of B in equ ii (3) = 9A+12B=54
- 4A+3B= 17 by coefficient of B in equ i (4) = 16A+12B=68
- subtract equation i from equation ii, since sign is the same in both equations
- 9A+12B-(16A+12B)= 54-68
- open bracket
- 9A+12B-16A-12B= 54-68= -14
- 9A-16A+12B-12B= -14
- -7A= -14
- divide both sides by -7
A = -14/-7= 2
Since the brand X dog food is represented as A
the cost of brand x dog food is $2
7.37:
a. <em>W</em> follows a chi-squared distribution with 5 degrees of freedom. See theorem 7.2 from the same chapter, which says

is chi-squared distributed with <em>n</em> d.f.. Here we have
and
.
b. <em>U</em> follows a chi-squared distribution with 4 degrees of freedom. See theorem 7.3:

is chi-squared distributed with <em>n</em> - 1 d.f..
c. <em>Y₆</em>² is chi-square distributed for the same reason as <em>W</em>, but with d.f. = 1. The sum of chi-squared distributed random variables is itself chi-squared distributed, with d.f. equal to the sum of the individual random variables' d.f.s. Then <em>U</em> + <em>Y₆</em>² is chi-squared distributed with 5 + 1 = 6 degrees of freedom.
7.38:
a. Notice that

and see definition 7.2 for the <em>t</em> distribution. Since <em>Y₆</em> is normally distributed with mean 0 and s.d. 1, it follows that this random variable is <em>t</em> distributed with 5 degrees of freedom.
b. Similar manipulation gives

so this r.v. is <em>t</em> distributed with 4 degrees of freedom.
Answer:

Step-by-step explanation:
To write the equation of a circle, use the formula
where the center of the circle is (h, k).
This means the equation is
.
Find the radius r by finding the distance between (3,2) and (9,3) using the distance formula.

Since the radius is √37 and therefore
.
The equation is
.
Answer:
n= -5
Step-by-step explanation:
Answer:
A
Step-by-step explanation:
by putting the value of x
ans was A