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2 years ago

Write the explicit rule for this arithmetic sequence 9,12,15,18…

Mathematics

1 answer:

MArishka [77]2 years ago

4 0

Answer:

an=9+(n−1)3, an=3n+6

Step-by-step explanation:

Arithmetic Sequence:

d=3

This is the formula of an arithmetic sequence.

an=a1+d(n−1)

Step 1: Substitute in the values of

a1=9 and d=3.

an=9+(3)(n−1)

Step 2: Simplify each term.

an=9+3n−3

Step 3: Subtract 3 from 9.

an=3n+6

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Which set of ordered pairs is not a function?

USPshnik [31]

The correct answer is B

3 0

2 years ago

A researcher is going to estimate the average typing speed of students of a college. He selects a random sample of 20 students a

Stella [2.4K]

Answer:

The margin of error of the 90% confidence interval of a student's average typing speed is of 1.933 wpm.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is 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 = 20 - 1 = 19

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 19 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.9}{2} = 0.95$ . So we have T = 1.7291

The margin of error is:

$M = T\frac{s}{\sqrt{n}}$

In which s is the standard deviation of the sample and n is the size of the sample. For this question, we have $s = 5, n = 20$ . So

$M = T\frac{s}{\sqrt{n}}$

$M = 1.7291\frac{5}{\sqrt{20}}$

$M = 1.933$

The margin of error of the 90% confidence interval of a student's average typing speed is of 1.933 wpm.

8 0

2 years ago

7.3 x 10^5 + 3.7 x 10^5=

Scilla [17]

Answer:

1100000

Step-by-step explanation:

5 0

2 years ago

What is the solution to -3x+5?

ziro4ka [17]

Answer:

x = 5/3

Step-by-step explanation:

-3x+5

-5= -3x

-5/-3 = 5/3

7 0

10 months ago

The maximum value of the function: f(x)= -5 x ^2 +30x-200 is?

VARVARA [1.3K]

Answer:

$\displaystyle - 155$

Step-by-step explanation:

we are given a quadratic function

$\displaystyle f(x) = - 5 {x}^{2} + 30x - 200$

we want to figure out the minimum value of the function

to do so we need to figure out the minimum value of x in the case we can consider the following formula:

$\displaystyle x _{ \rm min} = \frac{ - b}{2a}$

the given function is in the standard form i.e

$\displaystyle f(x) = a {x}^{2} + bx + c$

so we acquire:

b=30
a=-5

thus substitute:

$\displaystyle x _{ \rm min} = \frac{ - 30}{2. - 5}$

simplify multiplication:

$\displaystyle x _{ \rm min} = \frac{ - 30}{ - 10}$

simply division:

$\displaystyle x _{ \rm min} = 3$

plug in the value of minimum x to the given function:

$\displaystyle f (3)= - 5 {(3)}^{2} + 30.3 - 200$

simplify square:

$\displaystyle f (3)= - 5 {(9)}^{} + 30.3 - 200$

simplify multiplication:

$\displaystyle f (3)= - 45 + 90- 200$

simplify:

$\displaystyle f (3)= - 155$

hence,

the minimum value of the function is -155

5 0

2 years ago