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2 years ago

How do I solve this?

Mathematics

1 answer:

lakkis [162]2 years ago

3 0

Answer:

$\large\boxed{4\sqrt{-81}+\sqrt{-25}=41i}$

Step-by-step explanation:

$i=\sqrt{-1}\\\\\sqrt{-81}=\sqrt{(81)(-1)}=\sqrt{81}\cdot\sqrt{-1}=9i\\\\\sqrt{-25}=\sqrt{(25)(-1)}=\sqrt{25}\cdot\sqrt{-1}=5i\\\\4\sqrt{-81}+\sqrt{-25}=4(9i)+5i=36i+5i=41i$

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Divide.<br><br> −2 4/7<br><br> Enter your answer as a mixed number, in simplified form, in the box.

Katarina [22]

Answer:
-3 $\frac{3}{7}$

Explanation:
$\frac{-24}{7}$ = -3 $\frac{3}{7}$
So first make the improper fraction into a mixed number by taking out all the whole numbers from the numerator (3) and making sure the proper sign is in front of the answer (- 3) your remainder is the original numerator minus the product of the answer times the denominator: 24 - (3 • 7) = 24 - 21 = 3. Rewrite the mixed number.

3 0

2 years ago

For the hypothesis test H0: μ = 10 against H1: μ >10 and variance known, calculate the Pvalue for each of the following test

Basile [38]

Answer:

a) $p_v =P(Z>2.05)=1-P(z$

b) $p_v =P(Z>-1.84)=1-P(z$

c) $p_v =P(Z>0.4)=1-P(z$

Step-by-step explanation:

Some previous concepts

The p-value is the probability of obtaining the observed results of a test, assuming that the null hypothesis is correct.

A z-test for one mean "is a hypothesis test that attempts to make a claim about the population mean(μ)".

The null hypothesis attempts "to show that no variation exists between variables or that a single variable is no different than its mean"

The alternative hypothesis "is the hypothesis used in hypothesis testing that is contrary to the null hypothesis"

Hypothesis

Null hypothesis: $\mu=10$

Alternative hypothesis: $\mu >10$

If the random variable is distributed like this: $X \sim N(\mu,\sigma)$

We assume that the variance is known so the correct test to apply here is the z test to compare means, the statistic is given by the following formula:

$z_o=\frac{\bar X -\mu}{\sigma}$

Since we have the values for the statistic already calculated we can calculate the p value using the following formulas:

Part a

$p_v =P(Z>2.05)=1-P(z$

And in order to find the answer using excel we can use the following code:

"=1-NORM.DIST(2.05,0,1,TRUE)"

Part b

$p_v =P(Z>-1.84)=1-P(z$

And in order to find the answer using excel we can use the following code:

"=1-NORM.DIST(-1.84,0,1,TRUE)"

Part c

$p_v =P(Z>0.4)=1-P(z$

And in order to find the answer using excel we can use the following code:

"=1-NORM.DIST(0.4,0,1,TRUE)"

Conclusions

If we use a reference value for the significance, let's say $\alpha=0.05$ . For part a the $p_v$ so then we can reject the null hypothesis at this significance level.

For part b the $p_v>\alpha$ so then we FAIL to reject the null hypothesis at this significance level.

For part c the $p_v>\alpha$ so again we FAIL to reject the null hypothesis at this significance level.

3 0

2 years ago

What's 2/4 x 1/3? And pls provide work on how u got the answer.

igomit [66]

Just multiply the top number by the top number and the bottom numbers by the bottom numbers so

2/4 times 1/3=(2 times 1)/(4 times 3)=2/12

so to simplify, we find the ones exg 4/8=1/2 because 1/2 times 4/4=4/8 and 4/4 cancels out so

2/12=2/2 times 1/6
=1/6

8 0

2 years ago

Read 2 more answers

An experiment requires the population of the bacteria to reach 2 million before the experiment can begin. The reproduction rate

Furkat [3]

Answer:

about 6 hours

Step-by-step explanation:

$8( {7}^{x} ) = 2( {10}^{6} )$