Evaluate the algebraic expression for the given value(s) of the variable(s).

2x 2 - 7xy + 3y 2 ; x = -3, y = 4

Answer:

a) The 95% confidence interval for the lead concentration in water from this source is between 11.23 µg/L and 13.77 µg/L.

b) The upper bound of the confidence interval is less than 14 µg/L, which means that yes, we can conclude that the lead concentration is less than 14µg/L.

Step-by-step explanation:

We have the standard deviation for the samples, which mean that the t-distribution will be used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 12 - 1 = 11

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 11 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.201

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.201\frac{2}{\sqrt{12}} = 1.27[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 12.5 - 1.27 = 11.23 µg/L.

The upper end of the interval is the sample mean added to M. So it is 12.5 + 1.27 = 13.77 µg/L.

The 95% confidence interval for the lead concentration in water from this source is between 11.23 µg/L and 13.77 µg/L.

(b) Can you conclude that the lead concentration is less than 14µg/L?

The upper bound of the confidence interval is less than 14 µg/L, which means that yes, we can conclude that the lead concentration is less than 14µg/L.

Answer:

1713

Step-by-step explanation:

952+288+472=1713

Answer:

a=8 b=3/2

Step-by-step explanation:

so here a is the initial value which 8

then we can plug in 2 for x and 18 for f(x) to find b

f(x)=8*b^x

18=8*b^2

18/8=b^2

9/4=b^2

b^2=(3/2)^2

b=3/2

9514 1404 393

Answer:

  12 square inches

Step-by-step explanation:

The area is given by the formula ...

  A = 1/2bh

Here, the base is 6 inches and the height is given as 4 inches. Then the area is ...

  A = (1/2)(6 in)(4 in) = 12 in²

The area of the triangle is 12 square inches.

_____

Comment on the problem

Since you are given the base and height, we presume you are intended to use the formula above. You are also given all three side lengths. If you use the appropriate formula with those, you find the area is about 15.6 square inches. (The height of this triangle is actually closer to 5.2 inches.)

The figure represents a geometry that cannot exist. With the given base and height, the side lengths should be 5, not 6.

Answer:

The answer is 39.

Step-by-step explanation:

The average is the total amount of blood tests divided by the number of days.

Total: 36 + 43 + 29 + 48 = 156 blood tests / 4 days =  39 blood tests per day.

Answer:

A. True

Step-by-step explanation:

I majored in Mathematics

Answer:

y=6!

Step-by-step explanation:

you can easily see it on the graph. on the x axis, 2 is equivalent to 6

Answer:

When x is 2 y equals 6.

Step-by-step explanation:

You go right on the graph two units then go up the y axis till the line intersects the lines. In this case the graphed point is (2,6)

Answer: 47 and 48

Step-by-step explanation: 10/21 ≈0.476190476 and multiplied by a 100 to get a percentage is ≈ 47.6 which is in between 47 and 48. Hope this helps, and have a great day!

Answer: 47%

Step-by-step explanation:

half of 20 is 10 so half of 21 is 10.5

Answer:10 2/3 feet

Step-by-step explanation: 8 times 4/3= 32/3=10 2/3 feet

Answer:

The annual percentage yield is of 2.78%.

Step-by-step explanation:

Annual percentage yield of an account:

The annual percentage yield of an account compounded n times during the year with a decimal interest rate of r is given by:

[tex]Y = (1+\frac{r}{n})^n - 1[/tex]

Pays 2.75% compounded quarterly

This means that [tex]r = 0.0275, n = 4[/tex]. So

[tex]Y = (1+\frac{r}{n})^n - 1[/tex]

[tex]Y = (1+\frac{0.0275}{4})^4 - 1[/tex]

[tex]Y = 0.0278[/tex]

0.0278 = 2.78%

The annual percentage yield is of 2.78%.

Answer:

8

Step-by-step explanation:

I can't see the pic.

Answer:

$440

Step-by-step explanation:

40x11=440

hope it helped

plz mark me as brainliest.

Answer:

162

Step-by-step explanation:

Answer:

The missing number would be 17

Step-by-step explanation:

Answer: I think it’s 7

Step-by-step explanation:

Answer: 3.19

Step-by-step explanation:

So to find the average I used a simple but pretty effective method

3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+3+8/26=3.1923

So the new average is 3.19

Answer:

i think B

Step-by-step explanation:

Answer:

This is actually easy.

You need to multiply the term outside the bracket with the ones in the bracket (I hope I make sense lol)

Answer is 50 + 10n

Answer:

me

Step-by-step explanation:

becaus im the bes guy

Answer:

Okay ill do it from the ones given

Verbal Description:

Well it seems like Mike is charging a one time fee of 50 dollars each no matter what and after that its 30 dollars per hour.

Equation:

Assuming X is hours and C is total cost

50+30x= C

Table: (this will be in the order of hours, process and total)

0- (50+30*0) -0

1- (50+30*1) -80

2- (50+30*2) -110

3- (50+30*3) -140

4- (50+30*4) -170

5- (50+30*5) -200

6- (50+30*6) -230

Graph:

There are no instructions or questions for graph but if there is let me know in the comments

Questions:

#1) The rate of change for the graph is 30 dollars per hour or 30/1. Since for every hour its +30 plus the one time fee.

#2) The y-intercept here is 50 or in this case the one time payment fee.

The full question with the answer options is as follows:

Each figure below represents a fraction. Which figure is NOT equivalent to the others?

the answer options are as follows:

a.  [tex]\frac{2}{3}[/tex]

b.  [tex]\frac{4}{6}[/tex]

c.  [tex]\frac{3}{4}[/tex]

d. [tex]\frac{8}{12}[/tex]

Answer:

The correct answer is c:

Step-by-step explanation:

To know when two or more fractions are equivalent, we must multiply the numerator of one fraction by the denominator of the other fraction, the result must be the same value.

[tex]\frac{2}{3} x \frac{4}{6}[/tex] =   (2x6) =12   ;  (3x4)=12

[tex]\frac{2}{3} x \frac{8}{12}[/tex] = (2x12)=24 ;    (3x8) =24

[tex]\frac{4}{6} x \frac{8}{12}[/tex] = (4x12)=48;     (6x8)=48

Answer: interest rate was 6.7 %

Step-by-step explanation: 402/6000 = 0.067 = 6.7%

Answer:

so is the value of six times 1

Step-by-step explanation:

Answer:

Let x=sinθ

2sin²θ = 5sinθ - 3

2x²=5x-3

2x²-5x+3=0

(2x-3)(x-1)=0

2x-3=0 or x-1=0

x=3/2 or x=1

sinθ=2/3 or sinθ=1

θ=arcsin(2/3) or θ=arcsin(1)

θ=0.729727656 or θ=1.57079633=π/2

Answer:

8

Step-by-step explanation:

Let us assume the following things

x be no of 5 rupees coins

y be no of 2 rupees coins

z be no of 1 rupees coins

Now accoridng to the question

5x + 2y + z = 41

x + y + z = 20

y = 3x

Now do the elimination of variables

So,  

4x + y = 21

7x= 21

x = 3

y = 9

z= 8

hence, the 1-rupee coin would be 8

Answer:

C) CA=40

Step-by-step explanation:

2y/(2y+4)=(2y+6)/4y

cross multiply

8y²=4y²+20y+24

4(2y²)=4(y²+5y+6)

divide both sides by 4

2y²=y²+5y+6

y²-5y-6=0

(y-6)(y+1)=0

So the answer must be either 6 or -1.  Since it can't be a negative number, it must be 6.

CA=2(6)+4+4(6)

CA=12+4+24

CA=40

Answer:

At 2:00.

Step-by-step explanation:

You take 10 minutes off 2:50 for play time add the two 20s together then subtract 40 to get 2:00.

Answer:

[tex]cotθ = \frac{7 \sqrt{51} }{51} [/tex]

[tex]sinθ = \frac{ \sqrt{51} }{10} [/tex]

[tex]cscθ = \frac{10 \sqrt{51} }{51} [/tex]

Step-by-step explanation:

Please see the attached picture for the full solution.

Step-by-step explanation:

Area of triangle = 1/2×base×height

= 1/2×32×18

= 288in²