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2 years ago

(x2y-3y2+5xy2)-(-x2y+3xy2-3y2)

Mathematics

1 answer:

Reil [10]2 years ago

8 0

2x2y+8xy2-6y2 .........

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What is the next term in the sequence below? -324,108,-36,12,...

liq [111]

This is a geometric sequence with a common ratio of -1/3 and an initial term of -324. Any geometric sequence can be expressed as:
a(n)=ar^(n-1), in this case a=-324 and r=-1/3 so
a(n)=-324(-1/3)^(n-1) so the 5th term will be
a(5)=-324(-1/3)^4
a(5)=-324/81
a(5)= -4

5 0

3 years ago

Read 2 more answers

A university found that 20% of its students withdraw without completing the introductory statistics course. Assume that 20 stude

EleoNora [17]

Answer:

a) $P(X \leq 2)= P(X=0)+P(X=1)+P(X=2)$

And we can use the probability mass function and we got:

$P(X=0)=(20C0)(0.2)^0 (1-0.2)^{20-0}=0.0115$

$P(X=1)=(20C1)(0.2)^1 (1-0.2)^{20-1}=0.0576$

$P(X=2)=(20C2)(0.2)^2 (1-0.2)^{20-2}=0.1369$

And adding we got:

$P(X \leq 2)=0.0115+0.0576+0.1369 = 0.2061$

b) $P(X=4)=(20C4)(0.2)^4 (1-0.2)^{20-4}=0.2182$

c) $P(X>3) = 1-P(X \leq 3) = 1- [P(X=0)+P(X=1)+P(X=2)+P(X=3)]$

$P(X=0)=(20C0)(0.2)^0 (1-0.2)^{20-0}=0.0115$

$P(X=1)=(20C1)(0.2)^1 (1-0.2)^{20-1}=0.0576$

$P(X=2)=(20C2)(0.2)^2 (1-0.2)^{20-2}=0.1369$

$P(X=3)=(20C3)(0.2)^3 (1-0.2)^{20-3}=0.2054$

And replacing we got:

$P(X>3) = 1-[0.0115+0.0576+0.1369+0.2054]= 1-0.4114= 0.5886$

d) $E(X) = 20*0.2= 4$

Step-by-step explanation:

Previous concepts

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".

Solution to the problem

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=20, p=0.2)$

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:

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

Part a

We want this probability:

$P(X \leq 2)= P(X=0)+P(X=1)+P(X=2)$

And we can use the probability mass function and we got:

$P(X=0)=(20C0)(0.2)^0 (1-0.2)^{20-0}=0.0115$

$P(X=1)=(20C1)(0.2)^1 (1-0.2)^{20-1}=0.0576$

$P(X=2)=(20C2)(0.2)^2 (1-0.2)^{20-2}=0.1369$

And adding we got:

$P(X \leq 2)=0.0115+0.0576+0.1369 = 0.2061$

Part b

We want this probability:

$P(X=4)$

And using the probability mass function we got:

$P(X=4)=(20C4)(0.2)^4 (1-0.2)^{20-4}=0.2182$

Part c

We want this probability:

$P(X>3)$

We can use the complement rule and we got:

$P(X>3) = 1-P(X \leq 3) = 1- [P(X=0)+P(X=1)+P(X=2)+P(X=3)]$

$P(X=0)=(20C0)(0.2)^0 (1-0.2)^{20-0}=0.0115$

$P(X=1)=(20C1)(0.2)^1 (1-0.2)^{20-1}=0.0576$

$P(X=2)=(20C2)(0.2)^2 (1-0.2)^{20-2}=0.1369$

$P(X=3)=(20C3)(0.2)^3 (1-0.2)^{20-3}=0.2054$

And replacing we got:

$P(X>3) = 1-[0.0115+0.0576+0.1369+0.2054]= 1-0.4114= 0.5886$

Part d

The expected value is given by:

$E(X) = np$

And replacing we got:

$E(X) = 20*0.2= 4$

3 0

2 years ago

A patient is to take 4 2/3 tablespoons of medicine per day in 4 equally divided doses. How much medicine is to be taken in each

anygoal [31]

Answer:

1 1/6

Step-by-step explanation:

4 2/3 ÷ 4

Convert the mixed number into an improper fraction:

4 2/3 = 14/3

14/3 ÷ 4

14/3 ÷ 4/1

Use cdf (copy dot flip)

14/3 × 1/4

14 × 1 / 3 × 4

14/12

Convert improper fraction into a mixed number:

14/12 = 1 2/12

1 1/6

6 0

2 years ago

What is the slope of the line which passes through (−2, 0) and (0, 4)? (5 points) 2 Undefined −2 0

krek1111 [17]

Answer:

The answer is option 1.

Step-by-step explanation:

You have to apply Gradient formula :

$m = \frac{y2 - y1}{x2 - x1}$

$let \: (x1 \: , \: y1) \: be \: ( - 2 \: , \: 0)$

$let \: (x2 \: , \: y2) \: be \: (0 \: , \: 4)$

$m = \frac{4 - 0}{0 - ( - 2)}$

$m = \frac{4}{2}$

$m = 2$

6 0

2 years ago

Read 2 more answers

How would I do this? What would it be?

Igoryamba

Answer: $x=80$

Step-by-step explanation:

By definition, the sum of the exterior angles of a polygon is 360 degrees.

Knowing this, you can write the following equation:

$(x+8)+(2x+12)+(x+20)=360$

Then, you must solve for "x" in order to find its value. To do it, you can follow these steps:

1. You need to add the like terms:

$(x+8)+(2x+12)+(x+20)=360\\\\4x+40=360$

2. Now, subtract 40 from both sides of the equation:

$4x+40-(40)=360-(40)\\\\4x=320$

3. Finally, you must divide both sides of the equation by 4. Then:

$\frac{4x}{4}=\frac{320}{4}\\\\x=80$

7 0

3 years ago