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2 years ago

What is an explicit formula for an arithmetic sequence with a common difference of -2 and whose first term is one?

Mathematics

1 answer:

joja [24]2 years ago

3 0

Answer:

$a_{n}$ = - 2n +3

Step-by-step explanation:

the explicit formula for an arithmetic sequence is

$a_{n}$ = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

here a₁ = 1 and d = - 2 , then

$a_{n}$ = 1 - 2(n - 1) = 1 - 2n + 2 = - 2n + 3

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Agata [3.3K]

The median thickness of the entire glacier is calculated with the arranging the given dimensions of the thickness from least to highest.
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3 years ago

SAT verbal scores are normally distributed with a mean of 433 and a standard deviation of 90. Use the Empirical Rule to determin

laila [671]

34% of the scores lie between 433 and 523.

Solution:

Given data:

Mean (μ) = 433

Standard deviation (σ) = 90

<u>Empirical rule to determine the percent:</u>

(1) About 68% of all the values lie within 1 standard deviation of the mean.

(2) About 95% of all the values lie within 2 standard deviations of the mean.

(3) About 99.7% of all the values lie within 3 standard deviations of the mean.

$$Z(X)=\frac{x-\mu}{\sigma}$

$$Z(433)=\frac{433-\ 433}{90}=0$

$$Z(523)=\frac{523-\ 433}{90}=1$

Z lies between o and 1.

P(433 < x < 523) = P(0 < Z < 1)

μ = 433 and μ + σ = 433 + 90 = 523

Using empirical rule, about 68% of all the values lie within 1 standard deviation of the mean.

i. e. $((\mu-\sigma) \ \text{to} \ (\mu+\sigma))=68\%$

Here μ to μ + σ = $\frac{68\%}{2} =34\%$

Hence 34% of the scores lie between 433 and 523.

8 0

3 years ago

Help me out here guys

kvasek [131]

D.

f(x) can be written as (x+2)(x-2)(x-1)
by using difference of two squares to expand x^2 - 4 whch yields 3 x intercepts

similarly, k(x) can be written as
x(x+5)(x-5) which also yields 3
x intercepts (0,-5, and 5)

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2 years ago

Ben says the angle is an acute angle. Jeff says the angle is less than a straight angle. Explain whether their statements are co

Dahasolnce [82]

Answer:

sometimes, if their average angle is over 45 degrees

never are 2 obtuse angles summing to 180 degrees

always. two 90 degree angles always sum to 180 which is a straight line

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2 years ago

A water tank is 3/4 full.

guapka [62]

x/.75=x-56/0.4

0.4x=.75x-42

-0.35x=-42

x=120

I set up a proportion in which x=the tank when it is 3/4 full. When the tank is 3/4 full, solving the proportion tells us the x=120 litres. 120/3=40, and 120+40 is 160, showing that a tank completely full would indeed hold 160 litres.

Hope this helps!

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3 years ago