How to round 65.85 to the nearest tenth

Which domain restrictions apply to the rational expression?

andre [41]

Both expression have the same denominator: 9x²-1. Thus it must not be 0.

9x²-1=(3x-1)(3x+1)=0, resulting x=+-1/3.

Restrictions: x in R\{-1/3, 1/3}

Adding those expressions:

E=(-x-2)/(9x²-1 ) + (-5x+4)/(9x²-1)=

(-x-2-5x+4)/(9x²-1)=(-6x+2)/(9x²-1)=

(-2)(3x-1)/(9x²-1)=-2/(3x+1)

E=-2/(3x+1)

4 0

3 years ago

Christy bought a 9- foot piece of lumber trim bookshelf. Altogether, she needs 100 inches of lumber. Did Christy buy enough lumb

a_sh-v [17]

Answer:

Yes.

Step-by-step explanation:

because 9 feet converted to inches equals 108 inches, we know this because we can convert feet to inches via multiplication. To do this, simply multiply the given number (9) by 12 to get your answer.

5 0

2 years ago

In a study of 420,095 Danish cell phone users, 135 subjects developed cancer of the brain or nervous system (based on data from

Maksim231197 [3]

Answer:

$z=\frac{0.0003214 -0.00034}{\sqrt{\frac{0.00034(1-0.00034)}{420095}}}=-0.654$

$p_v =2*P(Z$

So the p value obtained was a very high value and using the significance level given $\alpha=0.005$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say that the true proportion not differs significantly from the specified value of 0.00034 or 0.034%.

Step-by-step explanation:

1) Data given and notation

n=420095 represent the random sample taken

X=135 represent the subjects developed cancer of the brain or nervous system (based on data from the Journal of the National Cancer Institute as reported in USA Today)

$\hat p=\frac{135}{420095}=0.0003214$ estimated proportion of subjects developed cancer of the brain or nervous system (based on data from the Journal of the National Cancer Institute as reported in USA Today)

$p_o=0.00034$ is the value that we want to test

$\alpha=0.005$ represent the significance level

Confidence=99.5% or 0.995

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that the brain or nervous system at a rate that is different from the rate of 0.0340% :

Null hypothesis: $p=0.00034$

Alternative hypothesis: $p \neq 0.00034$

When we conduct a proportion test we need to use the z statistic, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.0003214 -0.00034}{\sqrt{\frac{0.00034(1-0.00034)}{420095}}}=-0.654$

4) Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha=0.005$ . The next step would be calculate the p value for this test.

Since is a bilateral test the p value would be:

$p_v =2*P(Z$

So the p value obtained was a very high value and using the significance level given $\alpha=0.005$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can say that the true proportion not differs significantly from the specified value of 0.00034 or 0.034%.

4 0

3 years ago

When you substitute a value for x or y, you are x or y with a value.

Hitman42 [59]

Step-by-step explanation:

See whenever we have two variables like x and y.

And also we have given two equations in terms of x and y.

Example: ax + by = p and cx + dy = q

In order to get the solution, we need to find the value of x and y using the given two equations.

So here what we can do is:

Consider any one equation and get x or y from that equation.

i.e consider ax + by = p or x = $\frac{1}{a}*(p-by)$

Now plug value of x (or y) from the equation you have considered into the another equation.

i.e c( $\frac{1}{a}*(p-by)$ )+dy = q

Now solve this equation to get y (or x).

and after that we can find the other variable.

4 0

3 years ago

Read 2 more answers

Would You Rather? Snack Attack!

irga5000 [103]

Answer:

I would buy 8 bags of everyone's favorite snacks because it's cheaper and everyone gets what that want.

Step-by-step explanation:

This is just my opinion...Hope it helps

7 0

2 years ago