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2 years ago

Write and solve a proportion to answer the question.

Mathematics

2 answers:

kari74 [83]2 years ago

7 0

Answer:

$a = 25\% \: of \: 78 \\ a =\frac{25}{100} \times 78 \\ a = \frac{1}{4}\times 78 \\ \boxed{a = 19.5}$

<h3><u>a=19.5</u> is the right answer.</h3>

lyudmila [28]2 years ago

5 0

Answer:

uh i dont know but i think the other person answered thx

Step-by-step explanation:

You might be interested in

A cube has sides with a length of 1/3 cm. What is its volume?

kompoz [17]

Answer:

1 / 27 cm^3

Step-by-step explanation:

Given,

side = 1 / 3 cm

To find : Volume ( cube ) = ?

Formula : -

Volume ( cube ) = ( side )^3

Volume ( cube )

= ( 1 / 3 )^3

= 1^3 / 3^3

= 1 / 27

= 1 / 27 cm^3

7 0

2 years ago

Read 2 more answers

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.