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Citrus2011 [14]
3 years ago
9

What is the general term equation, an, for the arithmetic sequence 9, 5, 1, −3, . . . , and what is the 21st term of this sequen

ce?
Mathematics
1 answer:
marin [14]3 years ago
4 0
Hello : 
<span>the general term equation, an, for the arithmetic sequence is : 
An = A1+d(n-1)
A1 : the first term   and : d the common diference
in this exercice : 
A1 = 9
d =(-3)-(1) =(1)-(5) =(5) -(9) = -4
An = 9-4(n-1)
An = -4n +13</span>
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The EPA wants to know the daily level of pollutant discharge in the manufacturing district in Pittsburgh for February 2005. The
dangina [55]

Answer:

The 95% confidence interval for the true population mean of pollutant discharge is (26.7 tons, 33.7 tons).

Step-by-step explanation:

Let <em>X</em> represent the daily level of pollutant discharge in the manufacturing district in Pittsburgh.

The monitoring equipment reveals that for the 28 days of the February month

Mean daily discharge per factory, (\bar x) = 30.2 tons

Standard deviation daily discharge per factory, (<em>s</em>) = 9.1 tons

Compute the critical value of <em>t</em> for 95% level of confidence and (n - 1 =) 27 degrees of freedom as follows:

t_{0.05/2, 27}=2.052

*Use a t-table.

Compute the 95% confidence interval for the true population mean of pollutant discharge as follows:

CI=\bar x\pm t_{\alpha/2, (n-1)}\cdot\frac{s}{\sqrt{n}}

     =30.2\pm 2.052\times\frac{9.1}{\sqrt{28}}\\\\=30.2\pm 3.53\\\\=(26.67, 33.73)\\\\\approx (26.7, 33.7)

Thus, the 95% confidence interval for the true population mean of pollutant discharge is (26.7 tons, 33.7 tons).

4 0
3 years ago
If X and Y are distinct digits such that the eight-digit number 7448X24Y is divisible by both 8 and 9, then find X - Y.
Talja [164]

The value of X - Y such that the eight-digit number 7448X24Y is divisible by both 8 and 9 is 7

<h3>How to determine the distinct digits X and Y?</h3>

The eight-digit number is given as:

7448X24Y

Also, from the question

The number is divisible by 8 and 9

When a number is divisible by 8, then the last three digits of that number would be divisible by 8.

When a number is divisible by 9, the sum of the digits of the number would be divisible by 9.

So, we have:

24Y is divisible by 8

The possible value of Y from the above statement is 0

This is so because 240 is divisible by 8

The sum of the digits of the number would be divisible by 9.

This means that:

7 + 4 + 4 + 8 + X + 2 + 4 + Y = 29 + X + Y

Substitute 0 for Y

29 + X + Y = 29 + X + 0

Evaluate the sum

29 + X + Y = 29 + X

36 is divided by 9

So, we have

29 + X = 36

Subtract 29 from both sides of the equation

X = 7

So, we have

X = 7 and Y = 0

X - Y is calculated as:

X - Y = 7 - 0

Evaluate the difference in the above equation

X - Y = 7

Hence, the value of X - Y such that the eight-digit number 7448X24Y is divisible by both 8 and 9 is 7

Read more about digits at:

brainly.com/question/26856218

#SPJ1

7 0
2 years ago
Which product of prime polynomials is equivalent to 3x4 – 81x?
adelina 88 [10]

Given:

The expression is

3x^4-81x

To find:

The product of prime polynomials which is equivalent to the given expression.

Solution:

We have,

3x^4-81x

Taking out the common factors, we get

=3x(x^3-27)

It can be written as

=3x(x^3-3^3)

=3x(x-3)(x^2+3x+3^2)        [\because a^3-b^3=(a-b)(a^2+ab+b^2)]

=3x(x-3)(x^2+3x+3^2)

=3x(x-3)(x^2+3x+9)

Therefore, the correct option is B.

5 0
3 years ago
Read 2 more answers
15 is which percent of 30?<br> A. 450%<br> B. 200%<br> C. 50%<br> D. 1/2%<br> E. 2%
Hitman42 [59]

Answer:

answer: 50%

Step-by-step explanation:

The answer is 50% because 15 is half of 30 because 15 + 15 = 30 so 15 is half of 30 50%

7 0
3 years ago
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Can anyone me please
Y_Kistochka [10]

Answer:

Hi

Step-by-step explanation:

3 0
4 years ago
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