I need help with number 13, PLEASE. Extra points!

The polynomial given below has _____ root(s).2x2 + 5x + 2

Nastasia [14]

2x^2 + 5x + 2 = 0
(x + 2)(2x + 1) = 0
x = -2 x = - 1/2
Letter C

8 0

3 years ago

X∞n=0 (2 n + 1) x 2 n

Black_prince [1.1K]

Answer:3

If x=0 or x=1 it is trivial, so 0<x<1. Define a=1−x2, then 0<a<1.

Step-by-step explanation:

6 0

2 years ago

Please help me i will mark brainlest

valkas [14]

The answer is to the problem is 120 °

4 0

3 years ago

Test the hypothesis using the P value approach. Be sure the verify the requirements of the test.

Andreas93 [3]

Answer:

$p_v =2*P(z$

If we compare the p value and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion is not significantly different from 0.77.

Step-by-step explanation:

1) Data given and notation

n=500 represent the random sample taken

X=380 represent the number of people with some characteristic

$\hat p=\frac{380}{500}=0.76$ estimated proportion of adults that said that it is morally wrong to not report all income on tax returns

$p_o=0.76$ is the value that we want to test

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

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 true proportion is 0.7 .:

Null hypothesis: $p=0.77$

Alternative hypothesis: $p \neq 0.77$

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 $p_o$ .

Check for the assumptions that he sample must satisfy in order to apply the test

a)The random sample needs to be representative: On this case the problem no mention about it but we can assume it.

b) The sample needs to be large enough

$np_o =500*0.77=385>10$

$n(1-p_o)=384*(1-0.77)=115>10$

3) Calculate the statistic

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

$z=\frac{0.76-0.77}{\sqrt{\frac{0.77(1-0.77)}{500}}}=-0.531$

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 $\alpha=0.05$ . The next step would be calculate the p value for this test.

Since is a bilateral test the p value would be:

$p_v =2*P(z$

If we compare the p value and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion is not significantly different from 0.77.

6 0

3 years ago

A bag contains only red and blue marbles. Yasmine takes one marble at random from the bag. The probability that she takes a red

Daniel [21]

The answer is gonna be 40

8 0

3 years ago