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3 years ago

Determine the explicit formula of the following sequence -3,-18,-108...

Mathematics

1 answer:

kvv77 [185]3 years ago

3 0

Answer:

$a_{n}$ = - 3 $(6)^{n-1}$

Step-by-step explanation:

Note the common ratio r between consecutive terms, that is

r = - 18 ÷ - 3 = - 108 ÷ - 18 = 6

This indicates the sequence is geometric with n th term ( explicit formula )

$a_{n}$ = a $(r)^{n-1}$

where a is the first term and r the common ratio

Here a = - 3 and r = 6, thus

$a_{n}$ = - 3 $(6)^{n-1}$

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Complete the equation of the line through (4,-8) and (8,5).

Alisiya [41]

Slope = (5+8)/(8-4) = 13/4

y = mx + b
b= y - mx
b = -8 - (13/4) (4)
b = -8 -13
b = -21

equation
y = 13/4x - 21

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3 years ago

I need this please help

rjkz [21]

Answer:

a) sine
b) 9.8 ft

Step-by-step explanation:

The mnemonic SOH CAH TOA helps you remember the definitions of the trig functions. In particular, the function that involves the Opposite side and the Hypotenuse is the Sine function:

... Sin = Opposite/Hypotenuse

In this problem that means ...

... sin(55°) = x/(12 ft)

Multiplying by 12 ft, we have ...

... (12 ft)·sin(55°) = x ≈ 9.82982 ft ≈ 9.8 ft

7 0

3 years ago

A survey report states that 70% of adult women visit their doctors for a physical examination at least once in two years. If 20

irakobra [83]

Answer:

a) 0.3921 = 39.21% probability that fewer than 14 of them have had a physical examination in the past two years.

b) 0.107 = 10.7% probability that at least 17 of them have had a physical examination in the past two years.

Step-by-step explanation:

For each women, there are only two possible outcomes. Either they visit their doctors for a physical examination at least once in two years, or they do not. The probability of a woman visiting their doctor at least once in this period is independent of any other women. This means that we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

And p is the probability of X happening.

70% of adult women visit their doctors for a physical examination at least once in two years.

This means that $p = 0.7$

20 adult women

This means that $n = 20$

(a) Fewer than 14 of them have had a physical examination in the past two years.

This is:

$P(X < 14) = 1 - P(X \geq 14)$

In which

$P(X \geq 14) = P(X = 14) + P(X = 15) + P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20)$

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 14) = C_{20,14}.(0.7)^{14}.(0.3)^{6} = 0.1916$

$P(X = 15) = C_{20,15}.(0.7)^{15}.(0.3)^{5} = 0.1789$

$P(X = 16) = C_{20,16}.(0.7)^{16}.(0.3)^{4} = 0.1304$

$P(X = 17) = C_{20,14}.(0.7)^{17}.(0.3)^{3} = 0.0716$

$P(X = 18) = C_{20,18}.(0.7)^{18}.(0.3)^{2} = 0.0278$

$P(X = 19) = C_{20,19}.(0.7)^{19}.(0.3)^{1} = 0.0068$

$P(X = 20) = C_{20,20}.(0.7)^{20}.(0.3)^{0} = 0.0008$

$P(X \geq 14) = P(X = 14) + P(X = 15) + P(X = 16) + P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20) = 0.1916 + 0.1789 + 0.1304 + 0.0716 + 0.0278 + 0.0068 + 0.0008 = 0.6079$

$P(X < 14) = 1 - P(X \geq 14) = 1 - 0.6079 = 0.3921$

0.3921 = 39.21% probability that fewer than 14 of them have had a physical examination in the past two years.

(b) At least 17 of them have had a physical examination in the past two years

$P(X \geq 17) = P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20)$

From the values found in item (a).

$P(X \geq 17) = P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20) = 0.0716 + 0.0278 + 0.0068 + 0.0008 = 0.107$

0.107 = 10.7% probability that at least 17 of them have had a physical examination in the past two years.

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2 years ago

The rainfall amount last year was 6 inches below normal. The rainfall this year was 13 inches more than last year. What is the d

Lostsunrise [7]

Answer:

Step-by-step explanation:

The term difference means to subtract. Therefore, 13in - 6in, is equal to 7 inches.

13-6=7

Hope this Helps!!!

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3 years ago

A weather forecaster predicts that the temperature in antarctica will decrease 8 degreesf each hour for the next 6 hours how lon

Oliga [24]

What's the starting temperature?

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3 years ago