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3 years ago

Hurry i need your help

Mathematics

2 answers:

worty [1.4K]3 years ago

8 0

Answer:

IM READY FOR ACTION!

Step-by-step explanation:

GaryK [48]3 years ago

6 0

Answer: 10

Step-by-step explanation:

A. 2.50 + 2.50 + 2.50 + 2.50

the sum of 2.50, 4 times

B. The sum is 10, Maila's friends tell her to sell each wristband for 2.50. And 4 were bought, so add 2.50+2.50+2.50+2.50.

10 9 8 7 6 5 4 3 2 1 0

---0----|----|--•--|----|----•----|----|--•--|----|---

<----------- <---------- <----------- <------

+ + + +

2.50 2.50 2.50 2.50

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Sylvia, John, and Peter invested their savings in a bank. The ratio of the investment of Sylvia's to John's is 1: 3 and that of

Nastasia [14]

Answer:

4 : 12 : 15

Step-by-step explanation:

S : J = 1 : 3

J : P= 4 : 5

Using John's ratio to find a common ratio for all

S : J

(1 : 3)4 = 4 : 12

J : P

(4 : 5)3 = 12 : 15

Therefore our ratio is

S : J : P

4 : 12 : 15

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3 years ago

F(x) = x^2+3; g(x) = square root of x-2 find f(g(x))

Anettt [7]

F(g(x)) = x + 1 . Just replace square root of x-2 to x in f(x)

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3 years ago

Use elimination to solve the system

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3 years ago

What is the area of this trapezoid?

liberstina [14]

Answer:

$7.5\:\text{square units}$

Step-by-step explanation:

The area of a trapezoid is given by the average of the bases multiplied by the height.

What we're given:

Height of 3
Bases of 1 and 4

The average of the bases 1 and 4 is equal to $\frac{4+1}{2}=\frac{5}{2}=2.5$

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3 years ago

Read 2 more answers

In microbiology, colony-forming units (CFUs) are used to measure the number of microorganisms present in a sample. To determine

zimovet [89]

Answer:

(a) 0.2650

(b) 0.0111

(d) 0.0006

Step-by-step explanation:

Given that:

In microbiology, colony-forming units (CFUs) are used to measure the number of microorganisms present in a sample.

Suppose that the number of CFUs that appear after incubation follows a Poisson distribution with mean μ = 15. &;

If the area of the agar plate is 75cm²;

what is the probability of observing fewer than 4 CFUs in a 25 cm² area of the plate.

We can determine the mean number of CFUs that appear on a 25cm² area of the plate as follows;

75cm²/25cm² = 3

Since;

mean μ = 15

mean number of CFUs that appear on a 25cm² = 15/3 = 5 CFUs

Thus ; the probability of observing fewer than 4 CFUs in a 25 cm² area of the plate is estimated as:

= P(X < 4)

Using the EXCEL FUNCTION ( = poisson.dist(3, 5, TRUE) )

we have ;

P(X < 4) = 0.2650

b) If you were to count the total number of CFUs in 5 plates, what is the probability you would observe more than 95 CFUs?

Given that the total number of CFUs = 5 plates; then the mean number of CFUs in 5 plates = 15×5 = 75 CFUs

The probability is therefore = P( X > 95 )

= 1 - P(X ≤ 95)

= 1 - poisson.dist(95,75,TRUE) ( by using the excel function)

= 0.0111

c) Repeat the probability calculation in part (b) but now use the normal approximation.

Let assume that the mean and the variance of the poisson distribution are equal

Then;

$X \sim N (\mu = 75 , \sigma^2 = 75)$

We are to repeated the probability calculation in part (b) from above;

So:

P( X > 95 )

use the normal approximation

From standard normal variable table:

P(Z > 2.3094)

Using normal table

P(Z > 2.3094) = 0.0105

(d) Find the difference between this value and your answer in part (b).

So;

the difference between the value in part c and part b is;

= 0.0111 - 0.0105

$= 6*10^{-4}$

= 0.0006 to four decimal places

5 0

4 years ago