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3 years ago

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Zelina scored 10% higher on her second quiz than on her first quiz. On her third quiz, Zelina scored 20% higher than on her seco

nd quiz. Her third quiz score is what percent higher than her first quiz score?

1 answer:

pishuonlain [190]3 years ago

3 0

Answer:

30%

Step-by-step explanation:

you just add 10% and 20%

Hope it helps c:

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Drag numbers to complete the table for missing values of x, x2, x3

tresset_1 [31]

Top row is x= 10, x^2 =100, x^3 = 1000
Bottom row is 5, 25, 125

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4 years ago

Read 2 more answers

7. In A.ABC. JB and KA are medians, JK = 10x - 12, AB = 9x + 18, JM = 21, KM = 23. AJ = 60. and

Juliette [100K]

Answer:

A) JK and AB =

$[tex] \boxed{( \theta) = \f{12}{( \theta)} }$ So, =》 $\dfrac{10}{5} = \dfrac{1}{ \( \theta) }$ =》 $\( \theta) = \dfrac{5}{2}$ [/tex]

B) AABC

$[tex] \boxed{( \theta) = {1}{( \theta)} }$ So, $23}{-18=\\Ans } \boxed$

C) AABM:

$[tex] e \fbox{: }$ The value of k for which $\sin(jm) = \cos(x)$ is $\dfrac{\p}{2}$ ans[/tex]

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3 years ago

What is (5+3)+7=5+(3+7) is it Associative, Identity, Commutative or Substitution?

timama [110]

Answer:

Associative

Step-by-step explanation:

The associative property of addition states that you can add numbers however they are grouped inside parentheses.

It doesn't matter where you put the parentheses. You will always get the same answer.

For example,

$\begin{array}{rcl}(5 + 3) + 7 & = & 5 + (3 + 7)\\8 + 7& = & 5 + 10\\15 & = & 15\\\end{array}$

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3 years ago

The diagram the area of the large square is one square unit 2000 new segments divide a square into 4 equal sized triangles two o

sleet_krkn [62]

The answer is 0 because it cancels itself out

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3 years ago

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:

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

7 0

3 years ago