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3 years ago

Find the sum of the geometric sequence –3, 15, –75, 375, … when there are 8 terms

1 answer:

3 0

First, we need to solve for the common ratio from the data given by using the equation.

a(n) = a(1) r^(n-1)
15 = -3 r^(2-1)
-5 = r
r = -5

Then, we can find the sum by the expression:

S(n) = a(1) ( 1 - r^n) / 1-r
S(8) = -3 (1 + 5^8) / 1+5
S(8) = -195313

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What is the area of a triangle

Lady bird [3.3K]

The area of a triangle is 1/2 b/h. So what you do is you find base and height, multiply them together and whatever answer you got, you divide by 2.

Example:
A= 1/2 (b x h)
A= 1/2 (4 x 6)
A= 1/2 (24)
A= 12

Hope this helps!

7 0

3 years ago

A multiple choice test is composed of 10 questions. Each question has four possible answers, only one of the four possible answe

kompoz [17]

Answer:

Let X the random variable of interest "Number of correct anwers on the tet", on this case we now that:

$X \sim Binom(n=10, p=0.25)$

And the expected value is given by:

$E(X) = np =10*0.25 = 2.5$

Step-by-step explanation:

Previous concepts

A Bernoulli trial is "a random experiment with exactly two possible outcomes, "success" and "failure", in which the probability of success is the same every time the experiment is conducted". And this experiment is a particular case of the binomial experiment.

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

$nCx=\frac{n!}{(n-x)! x!}$

Solution to the problem

Let X the random variable of interest "Number of correct anwers on the tet", on this case we now that:

$X \sim Binom(n=10, p=0.25)$

And the expected value is given by:

$E(X) = np =10*0.25 = 2.5$

4 0

3 years ago

Can someone pls help me with this?

bija089 [108]

Communicative Property: (5+7) +3

Associative prop: (3+5) +7 or (3+7) +5

And the last one, I don’t fully understand what it is asking, but I believe it is asking for the answer which would be 15

7 0

3 years ago

Pls help me, will give brainliest.

xxMikexx [17]

Answer: i am almost positive its (A)

i really hope im not wrong because this answer is the only one that has a stable rising action going up by the same number it did with the number before it. if its not right then your other option is (D)

Step-by-step explanation:

8 0

2 years ago

Read 2 more answers

2(x-11)+5-1<br> What is x

dangina [55]

Answer:

Step-by-step explanation:

2(x-11) + 5-1

We can use the distributive property:

2x - 22 + 5 - 1

We can then simplify:

2x - 18

In this case, if 2x - 18 = 0, then 2x = 18 and x = 9.

5 0

3 years ago

Read 2 more answers