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xxTIMURxx [149]
3 years ago
13

Perchlorate is a chemical used in rocket fuel. People who live near a former rocket-testing site are concerned that perchlorate

is present in unsafe amounts in their drinking water. Drinking water is considered safe when the average level of perchlorate is 24.5 parts per billion (ppb) or less. A random sample of 28 water sources in this area produces a mean perchlorate measure of 25.3 ppb. Which of the following is an appropriate alternative hypothesis that addresses their concern?
A) H: 25.3.
B) H: > 25.3.
C) H u <24.5.
D) Hu> 24.5. 27.
Mathematics
1 answer:
ser-zykov [4K]3 years ago
8 0

Answer:

H_1 : \mu  > 24.5

Step-by-step explanation:

From the given information:

The sample size is 28

The population mean is 24.5 (ppb)

The sample mean is 225.3 (ppb)

Thus, the null and the alternative hypothesis can be computed as:

Null hypothesis:

H_o : \mu \le 24.5

Alternative hypothesis:

H_1 : \mu  > 24.5

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Sonya took out a mortgage of $65,000 at 7% for 25 years. What is the cost of the mortgage?
Vika [28.1K]

The cost of the mortgage is $81250

<h3>What are interests?</h3>


Interests are percentages of a principal

Given the following parameters

Principal = $65000

Rate = 7% = 0.07
Time = 5 years

<h3>Calculate the interest</h3>

I = PRT/100
I = 65000*0.07*25
I = 16,250

<h3>Determine the cost of the mortgage</h3>

Cost of mortgage = Principal + Interest

Cost of mortgage = 65000 + 16250
Cost of mortgage = 81,250

Hence the cost of the mortgage is $81250

Learn more on mortgage here: brainly.com/question/22846480

5 0
2 years ago
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Raquel takes her pulse in order to determine her resting heart rate, measured in beats per minute (\text{bpm})(bpm)left parenthe
murzikaleks [220]

Answer:

Raquel's heart rate is slower.

4 0
3 years ago
9. Ellie is making a batch of pancakes
Vikki [24]

Answer:

Step-by-step explanation:

Maybe your questions has some wrong numbers in it?  but, going by what's in your questions ,  just  1 cup of flour   :/   seems too easy

4 0
3 years ago
If the endpoints of the diameter of a circle are (−8, −6) and (−4, −14), what is the standard form equation of the circle? A) (x
Andrei [34K]

Answer:

\large\boxed{A.\ (x+6)^2+(y+10)^2=20}

Step-by-step explanation:

The standard form of an equation of a circle:

(x-h)^2+(y-k)^2=r^2

(h, k) - center

r - radius

We have the endpoints of the diameter of a circle (-8, -6) and (-4, -14).

The midpoint of a diameter is a center of a circle.

The formula of a midpoint:

\left(\dfrac{x_1+x_2}{2},\ \dfrac{y_1+y_2}{2}\right)

Substitute:

x=\dfrac{-8+(-4)}{2}=\dfrac{-12}{2}=-6\\\\y=\dfrac{-6+(-14)}{2}=\dfrac{-20}{2}=-10

We have h = -6 and k = -10.

The radius is the distance between a center and the point on a circumference of a circle.

The formula of a distance between two points:

d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}

Substitute (-6, -10) and (-8, -6):

r=\sqrt{(-8-(-6))^2+(-6-(-10))^2}=\sqrt{(-2)^2+4^2}=\sqrt{4+16}=\sqrt{20}

Finally we have

(x-(-6))^2+(y-(-10))^2=(\sqrt{20})^2\\\\(x+6)^2+(y+10)^2=20

5 0
3 years ago
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What is the value of x? Round your answer to the nearest tenth if necessary.
katen-ka-za [31]

So to start off:

The equation you will want to use for the hypotenuse is

A (squared) + B (squared) = C (squared)

So you will want to fill in the equation like so:

7(7) + 4(4) = C (squared)

So now that you have your information filled out, put it all together!

49 + 16 = 65

Now don't forget that the 65 is SQUARED!

You will want to use the SQUARE ROOT method to help with that!

So what you will want to do is think of the numbers that are PERFECT SQUARES.

A perfect square consist of

Here is the list of perfect squares 1-10:

1 x 1 = 1

2 x 2 = 4

3 x 3 = 9

4 x 4 = 16

5 x 5 = 25

6 x 6 = 36

7 x 7 = 49

8 x 8 = 64

9 x 9 = 81

So look closely at these perfect squares, Do you see where 65 will lie?

It will lie between 8 and 9.

So you will do the square root now.

√65

The answer will come out as:

<span>8.06225775</span>

<span>You will then round it to the nearest tenths place (one after the decimal)</span>

You will look at the two numbers behind the decimal which is

0.6.

As you know,(If you round the tenths place), if the number in the hundredths is 5 or HIGHER. It will round up the number in the tenths place to 1.

So as we know 6 is higher than 5 so your answer would be:

8.1

I hope this helped! :)

>^.^<

(      )~


3 0
3 years ago
Read 2 more answers
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