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3 years ago

20. Each student read 41 pages in December

Mathematics

2 answers:

Artemon [7]3 years ago

7 0

I would need to know how many students there are. Unless youre looking for an equation in which case its: 41x

azamat3 years ago

3 0

Answer:

I think 1,271 pages idk

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When the p-value is used for hypothesis testing, the null hypothesis is rejected if _____

pashok25 [27]

Answer:

Step-by-step explanation:

Here, we are to give the reason why we would reject the null hypothesis during the hypothesis testing.

In considering whether to accept the null hypothesis or reject the null hypothesis, we have to take into consideration two things.

The p-value and the alpha value. The p-value refers to the probability which is directly obtainable from the standard score which is referred to as the z-score while the alpha refers to the level of significance.

Now, when the p-value is less than alpha, we simply reject the null hypothesis and accept the alternative hypothesis. In a case however, we have the value of p greater than or equal to the significance level alpha, we simply accept the null hypothesis in this case.

The question asks for a rejection case and this can happen only when the p-value is less than the level of significance alpha

5 0

3 years ago

Can somebody please help me? I will mark brainiest if i can!<br> qr + r; use q = 3, and r = -6

Sveta_85 [38]

The answer is -12. R times -6 is -18 and -18 plus -6 is -12

5 0

3 years ago

Read 2 more answers

23. A certain type of gasoline is supposed to have a mean octane rating of at least 90. Suppose measurements are taken on of 5 r

Nostrana [21]

Answer:

a) $p_v =P(Z$

b) Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

c) $P(\bar X >90)=1-P(Z$

$1-P(Z$

d) For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

Step-by-step explanation:

Previous concepts and data given

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

We can calculate the sample mean and deviation with the following formulas:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

$s=\sqrt{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}$

$\bar X=88.96$ represent the sample mean

$s=1.011$ represent the sample standard deviation

n=5 represent the sample selected

$\alpha$ significance level

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is less than 90, the system of hypothesis would be:

Null hypothesis: $\mu \geq 90$

Alternative hypothesis: $\mu < 90$

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{88.96-90}{\frac{0.8}{\sqrt{5}}}=-2.907$

Part a

P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=5-1 = 4$

Then since is a left tailed test the p value would be:

$p_v =P(Z$

Part b

Since $p_v$ we can reject the null hypothesis at the significance level given. So based on this we can commit type of Error I.

Because Type I error " is the rejection of a true null hypothesis".

Part c

We want this probability:

$P(\bar X$

The best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\frac{\sigma}{\sqrt{n}}}$

If we apply this formula to our probability we got this:

$P(\bar X >90)=1-P(Z$

$1-P(Z$

Part d

For this case we need a z score that accumulates 0.02 of the area on the right tail and 0.98 on the left tail and this value is z=2.054

And we can use this formula:

$2.054=\frac{90-89}{\frac{0.8}{\sqrt{n}}}$

And if we solve for n we got:

$n = (\frac{2.054 *0.8}{1})^2=2.7 \approx 3$

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3 years ago

Solve the following equation: 4(8x + 2) = 72

Iteru [2.4K]

The x is 2 :) I hope it’s right! I’m pretty sure it is though !

6 0

3 years ago

What two rays that intersect at a common endpoint?

AVprozaik [17]

Vertex - The common endpoint of two rays at which an angle is formed.
Vertical Angles - Pairs of angles formed where two lines intersect.

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3 years ago