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3 years ago

7x + 2 > 30 Help please

Mathematics

2 answers:

elixir [45]3 years ago

4 0

Answer:

x > 4

Step-by-step explanation:

7x + 2 > 30

7x +2 -2 > 30-2

7x > 28

7x/7 > 28/7

x > 4

Alexeev081 [22]3 years ago

3 0

The answer to the question is x > 4

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Find the length of side e to the nearest tenth in the triangle below.

inessss [21]

Answer:12.1

Step-by-step explanation:

Angle D=180-(82+52)

Angle D=180-134

Angle D=46

Using sine rule

e/sinE=d/sinD

e/sin52=11/sin46

e/0.7880=11/0.7193

e/0.7880=15.29

Cross multiply

e=15.29 x 0.7880

e=12.05

e=12.1 approximately

4 0

3 years ago

A painting is purchased for $250. If the value of the painting doubles every 5 years, then

ch4aika [34]

After 5 years, value doubles.
Hence after 5 years, value is 250 x 2 = 500
After another 5 years, value doubles.
500 x 2 = 1000
Ans: $1000

7 0

2 years ago

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

3 years ago

Answerrr?? What is the answer to these two questions?..

asambeis [7]

15. 16 yards. Add side a (2 yds.) and b (6 yds.), divide by 2 and then multiply by the height (4 yds.)

16. I believe it would be 48 m. find the area of each rectangle and then add it. (6x2)+(12x3) -> 12+36= 48 square meters.

Hope it helps! -cat

4 0

3 years ago

For every 1 litre of water used to make a medicine, 269ml of sucrose and 61ml of saline solution are used. Express the amount of

Burka [1]

Answer:

Step-by-step explanation:

1 litre = 1000 ml

water : Sucrose : Saline = 1000 : 269 : 61

This is simplest form. We cannot reduce this as 61 is a prime number and 1000; 269 will not come in 61th table or

We can say 100 ; 269 ; 61 don't have common term

8 0

3 years ago