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3 years ago

When graphing inequalities, and you divide y by a negative number, do you switch the symbol?

Mathematics

1 answer:

xz_007 [3.2K]3 years ago

4 0

Yes you need to! And you need to be careful not to forgot that when doing your calculations!!

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Joaquim earns a salary of $4,000 per month plus a 6% commision on all of his sales. He wants to earn more than 7,000 next month.

andrew11 [14]

Answer:

s=salary

x=sales

s ≥ 4,000 + .06x

Step-by-step explanation:

3 0

3 years ago

The same as has greater then less than plz anwser I am struggling

xeze [42]

For each power of ten , the number of zeros written in the product is the same as the number of exponents.

3 0

3 years ago

Find the slope of f(x)=5x-4

frosja888 [35]

Answer:

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Please help and explain how you solved it. Thanks.

galina1969 [7]

Answer:

This is 0.14 to the nearest hundredth

Step-by-step explanation:

Firstly we list the parameters;

Drive to school = 40

Take the bus = 50

Walk = 10

Sophomore = 30

Junior = 35

Senior = 35

Total number of students in sample is 100

Let W be the event that a student walked to school

So P(w) = 10/100 = 0.1

Let S be the event that a student is a senior

P(S) = 35/100 = 0.35

The probability we want to calculate can be said to be;

Probability that a student walked to school given that he is a senior

This can be represented and calculated as follows;

P( w| s) = P( w n s) / P(s)

w n s is the probability that a student walked to school and he is a senior

We need to know the number of seniors who walked to school

From the table, this is 5/100 = 0.05

So the Conditional probability is as follows;

P(W | S ) = 0.05/0.35 = 0.1429

To the nearest hundredth, that is 0.14

3 0

3 years ago

Let the number of chocolate chips in a certain type of cookie have a Poisson distribution. We want the probability that a cookie

ludmilkaskok [199]

Answer:

$\lambda \geq 6.63835$

Step-by-step explanation:

The Poisson Distribution is "a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time or space if these events occur with a known constant mean rate and independently of the time since the last event".

Let X the random variable that represent the number of chocolate chips in a certain type of cookie. We know that $X \sim Poisson(\lambda)$

The probability mass function for the random variable is given by:

$f(x)=\frac{e^{-\lambda} \lambda^x}{x!} , x=0,1,2,3,4,...$

And f(x)=0 for other case.

For this distribution the expected value is the same parameter $\lambda$

$E(X)=\mu =\lambda$

On this case we are interested on the probability of having at least two chocolate chips, and using the complement rule we have this:

$P(X\geq 2)=1-P(X$

Using the pmf we can find the individual probabilities like this:

$P(X=0)=\frac{e^{-\lambda} \lambda^0}{0!}=e^{-\lambda}$

$P(X=1)=\frac{e^{-\lambda} \lambda^1}{1!}=\lambda e^{-\lambda}$

And replacing we have this:

$P(X\geq 2)=1-[P(X=0)+P(X=1)]=1-[e^{-\lambda} +\lambda e^{-\lambda}[]$

$P(X\geq 2)=1-e^{-\lambda}(1+\lambda)$

And we want this probability that at least of 99%, so we can set upt the following inequality:

$P(X\geq 2)=1-e^{-\lambda}(1+\lambda)\geq 0.99$

And now we can solve for $\lambda$

$0.01 \geq e^{-\lambda}(1+\lambda)$

Applying natural log on both sides we have:

$ln(0.01) \geq ln(e^{-\lambda}+ln(1+\lambda)$

$ln(0.01) \geq -\lambda+ln(1+\lambda)$

$\lambda-ln(1+\lambda)+ln(0.01) \geq 0$

Thats a no linear equation but if we use a numerical method like the Newthon raphson Method or the Jacobi method we find a good point of estimate for the solution.

Using the Newthon Raphson method, we apply this formula:

$x_{n+1}=x_n -\frac{f(x_n)}{f'(x_n)}$

Where :

$f(x_n)=\lambda -ln(1+\lambda)+ln(0.01)$

$f'(x_n)=1-\frac{1}{1+\lambda}$

Iterating as shown on the figure attached we find a final solution given by:

$\lambda \geq 6.63835$

4 0

3 years ago