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3 years ago

An EPA contractor needs to test the concentration of a substance in ten samples of the ground water. Seventy samples were

Mathematics

1 answer:

olga55 [171]3 years ago

7 0

Answer:

Systematic sampling

Step-by-step explanation:

An EPA contractor needing to test the concentration of a substance in ten samples out seventy samples provided form a single source at regular time intervals.

For the contractor to effectively carry out the testing he has to employ a Non-probability system of sampling which is called Systematic sampling, because in systematic sampling we can assume the population size (x ) which in this case is 70 and the sample size( n ) to be 10

He will have to select ; ( x / n )^th of the sampling frame for best results

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Nico was stunned when he opened the mail.Here was a check for $332.50 this is the interest he earned on his investment.One year

Mazyrski [523]

Answer:

Investment A = 3650

Investment B = 1350

Step-by-step explanation:

Given that:

Total interest earned = 332.50

Total Principal invested = 5000

Investment A:

Rate = 8%

Time = 1 year

Principal = a

Interest earned = 0.08a

Investment B:

Rate = 3%

Time = 1 year

Principal = b

Interest earned = 0.03b

a + b = 5000 ____(1)

0.08a + 0.03b = 332.50 - - - (2)

From (1)

a = 5000 - b

Into (2)

0.08(5000 - b) + 0.03b = 332.50

400 - 0.08b + 0.03b = 332.50

400 - 0.05b = 332.50

-0.05b = - 67.5

b = $1350

a = 5000 - b

a = 5000 - 1350

a = $3650

7 0

3 years ago

A Monarch Butterfly can fly 50 miles per day. How long would it take him to fly 2,500 miles?

lisov135 [29]

Answer:

50 days

Step-by-step explanation:

2500/50 = 50

Answer: 50 days

3 0

3 years ago

a recipe calls for 6 cups of water and 4 cups of flour. if the recipe is decreased to use 2 cups of water, how much flour should

Len [333]

$\frac{6}{4}=\frac{2}{f}\\\frac{3}{2}=\frac{2*\frac{3}{2}}{f*\frac{3}{2}}\\\frac{3}{2}=\frac{3}{\frac{3}{2}f}\\2=\frac{3}{2}f\\2*\frac{2}{3}=\frac{3}{2}f*\frac{2}{3}\\\frac{4}{3}=f$

1 1/3 cups of flour

3 0

3 years ago

The highest scorer of the women's basketball championship was Jessica Bradley. She scored more points than Tina Harner, her te

Arisa [49]

Answer:

Jessica Bradley - 856 Points

Tina Harner - 707 Points

Step-by-step explanation:

FULL QUESTION:

The highest scorer of the women's basketball championship was Jessica Bradley. She scored 149 more points than Tina Harner, her teammate. Together, Bradley and Harner scored 1563 points. How many points did each player score during the championship?

Let T = points scored by Tina Harner

J = points scored by Tina Harner

She scored 149 more points than Tina Harner, her teammate. This means;

J = T + 149...........(i)

Together, Bradley and Harner scored 1563 points. This means;

J + T = 1563 .........(ii)

How many points did each player score during the championship?

We have to find T and J.

Substitute value of J from eqn (i) into eqn (ii)

T + 149 + T = 1563

2T = 1563 - 149 = 1414

T = 1414 / 2 = 707

J = 707 + 149 = 856

Jessica Bradley - 856 Points

Tina Harner - 707 Points

3 0

3 years ago

2. Check the boxes for the following sets that are closed under the given

son4ous [18]

The properties of the mathematical sequence allow us to find that the recurrence term is 1 and the operation for each sequence is

a) Subtraction

b) Addition

c) AdditionSum

d) in this case we have two possibilities

* If we move to the right the addition

* If we move to the left the subtraction

The sequence is a set of elements arranged one after another related by some mathematical relationship. The elements of the sequence are called terms.

The sequences shown can be defined by recurrence relations.

Let's analyze each sequence shown, the ellipsis indicates where the sequence advances.

a) ... -7, -6, -5, -4, -3

We can observe that each term has a difference of one unit; if we subtract 1 from the term to the right, we obtain the following term

-3 -1 = -4

-4 -1 = -5

-7 -1 = -8

Therefore the mathematical operation is the subtraction.

b) $0. \sqrt{1}. \sqrt{4}, \sqrt{9}, \sqrt{16}, \sqrt{25}$ ...

In this case we can see more clearly the sequence when writing in this way

$0, \sqrt{1^2}. \sqrt{2^2}, \sqrt{3^2 } . \sqrt{4^2} , \sqrt{5^2}$

each term is found by adding 1 to the current term,

$\sqrt{(0+1)^2} = \sqrt{1^2} \\\sqrt{(1+1)^2} = \sqrt{2^2}\\\sqrt{(2+1)^2} = \sqrt{3^2}\\\sqrt{(5+1)^2} = \sqrt{6^2}$

Therefore the mathematical operation is the addition

c) $... \frac{-10}{2}. \frac{-8}{2}, \frac{-6}{2}, \frac{-4}{2}. \frac{-2}{2}. ...$

The recurrence term is unity, with the fact that the sequence extends to the right and to the left the operation is

To move to the right add 1

- $\frac{-10}{2} + 1 = \frac{-10}{2} - \frac{2}{2} = \frac{-8}{2}\\\frac{-8}{2} + \frac{2}{2} = \frac{-6}{2}$

To move left subtract 1

$\frac{-2}{2} - 1 = \frac{-4}{2}\\\frac{-4}{2} - \frac{2}{2} = \frac{-6}{2}$

Using the properties the mathematical sequence we find that the recurrence term is 1 and the operation for each sequence is

a) Subtraction

b) Sum

c) Sum

d) This case we have two possibilities

If we move to the right the sum

If we move to the left we subtract

Learn more here: brainly.com/question/4626313

5 0

3 years ago