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3 years ago

Find the common ratio of the geometric sequence − 1 , − 9 , − 81 ,

Mathematics

1 answer:

frozen [14]3 years ago

7 0

Step-by-step explanation:

everything can be found in the picture

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BRAINLIEST ANSWER FOR FIRST Please help with the problem below

Sidana [21]

Answer:

$m\:$ ]

Step-by-step explanation:

The given inequality is ;

$\frac{2m+3}{2}-\frac{17}{4}\:$

Multiply through by 8 to clear the fraction;

$4(2m+3)-2(17)\:$

Expand;

$8m+12-34\:$

Group similar terms;

$8m-m\:$

$7m\:$

$m\:$

7 0

3 years ago

Read 2 more answers

The school auditorium has 80 rows of seats. There are 50 seats in each row. What is the total number of seats in the chhool audi

Snezhnost [94]

The number of rows = 80

number of seats in 1 row = 50

total number of seats is the product of the number of rows and number of seats per row = 80*50 = 4000

6 0

3 years ago

Read 2 more answers

f) The life of a power transmission tower is exponentially distributed, with mean life 25 years. If three towers, operated indep

Step2247 [10]

Answer:

15.24% probability that at least 2 will still stand after 35 years

Step-by-step explanation:

To solve this question, we need to understand the binomial distribution and the exponential distribution.

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.

Exponential distribution:

The exponential probability distribution, with mean m, is described by the following equation:

$f(x) = \mu e^{-\mu x}$

In which $\mu = \frac{1}{m}$ is the decay parameter.

The probability that x is lower or equal to a is given by:

$P(X \leq x) = \int\limits^a_0 {f(x)} \, dx$

Which has the following solution:

$P(X \leq x) = 1 - e^{-\mu x}$

The probability of finding a value higher than x is:

$P(X > x) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-\mu x}$

Probability of a single tower being standing after 35 years:

Single tower, so exponential.

Mean of 25 years, so $m = 25, \mu = \frac{1}{25} = 0.04$

We have to find $P(X > 35)$

$P(X > 35) = 1 - P(X \leq x) = 1 - (1 - e^{-\mu x}) = e^{-0.04*35} = 0.2466$

What is the probability that at least 2 will still stand after 35 years?

Now binomial.

Each tower has a 0.2466 probability of being standing after 35 years, so $p = 0.2466$

3 towers, so $n = 3$

We have to find:

$P(X \geq 2) = P(X = 2) + P(X = 3)$

In which

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

$P(X = 2) = C_{3,2}.(0.2466)^{2}.(0.7534)^{1} = 0.1374$

$P(X = 3) = C_{3,3}.(0.2466)^{3}.(0.7534)^{0} = 0.0150$

$P(X \geq 2) = P(X = 2) + P(X = 3) = 0.1374 + 0.0150 = 0.1524$

15.24% probability that at least 2 will still stand after 35 years

4 0

3 years ago

X:y=5:3 and x+y=56 work out the value of x-y

Vladimir79 [104]

x - y = 14

given the ratio x : y = 5 : 3

then let x = 5x and y = 3x, hence equation can be expressed as

5x + 3x = 56

8x = 56 ( divide both sides by 8 )

x = 7

Hence x = 5 × 7 = 35 and y = 3 × 7 = 21

Thus x - y = 35 - 21 = 14

6 0

3 years ago

A sweater for 36.00 at 7% sales tax

blagie [28]

$36 x 1.07 = $38.52
The cost will be $38.52
Tax on this is $2.52

4 0

3 years ago