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2 years ago

100 pts help me please.

Mathematics

1 answer:

Natalija [7]2 years ago

7 0

Answer:

Carly's expenditure was $240 and the number of boxes of cards was required is 24 boxes.

Step-by-step explanation:

We know that:

48 + 8(b) = Carly's expenditure
10(b) = Carly's expenditure
48 + 8b = 10b
B = Boxes of cards

Work:

48 + 8b = 10b
=> 48 + 8b - 8b = 10b - 8b
=> 48 = 2b
=> b = 24

Now, let's substitute the value of b into any equation.

10(24)
=> 240

Hence, Carly's expenditure was $240 and the number of boxes of cards was required is 24 boxes.

Hoped this helped.

$BrainiacUser1357$

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nikitadnepr [17]

Answer:

$z=\frac{0.4 -0.33}{\sqrt{\frac{0.33(1-0.33)}{200}}}=2.105$

$p_v =P(z>2.105)=0.018$

If we compare the p value obtained and the significance level given $\alpha=0.01$ 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 1% of significance the proportion of students that had job at the school mentioned is not significantly higher then 0.33 .

Step-by-step explanation:

1) Data given and notation

n=200 represent the random sample taken

X=80 represent the number of students that had jobs

$\hat p=\frac{80}{200}=0.4$ estimated proportion of students that had jobs

$p_o=0.3333$ is the value that we want to test

$\alpha=0.01$ represent the significance level

Confidence=99% or 0.99

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 proportion of students that have jobs at the school mentioned is higher than the reported value at the article:

Null hypothesis: $p\leq 0.33$

Alternative hypothesis: $p > 0.33$

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 $p_o$ .

3) Calculate the statistic

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

$z=\frac{0.4 -0.33}{\sqrt{\frac{0.33(1-0.33)}{200}}}=2.105$

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 $\alpha=0.01$ . The next step would be calculate the p value for this test.

Since is a right tailed test the p value would be:

$p_v =P(z>2.105)=0.018$

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3 years ago

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grin007 [14]

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3 years ago

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Sphinxa [80]

Answer:

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Step-by-step explanation:

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3 years ago

PROBLEM: Riley has a rectangular shaped patio that is 13 feet long by 15 feet wide. He wants to DOUBLE THE AREA of the patio by

photoshop1234 [79]

Answer:

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Step-by-step explanation:

1) From Geometry we remember that area formula for the rectangle is represented by:

$A = x\cdot y$ (1)

Where:

$A$ - Area, measured in square feet.

$x$ - Length, measured in feet.

$y$ - Width, measured in feet.

From statement we know that Riley wants to double the area, that is:

$A' = 2\cdot A$ (2)

By applying (1) in (2), we get the following expression:

$A' = 2\cdot x\cdot y$ (3)

Given that Riley wants to double the area of the pation by increasing the length and width by the same amount, we can rearrange (3) by algebraic means:

$A' = \sqrt{2}\cdot \sqrt{2}\cdot x\cdot y$

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The equation that represents the total area of Riley's proposed ratio is $A' = (\sqrt{2}\cdot x)\cdot (\sqrt{2}\cdot y)$ .

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$y' = \sqrt{2}\cdot y$

$y' = \sqrt{2}\cdot (15\,ft)$

$y' \approx 21.2\,ft$

The length and width of the new patio are approximately 18.4 feet and 21.2 feet, respectively.

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2 years ago

tom sold half of his comic books and then bought six more. he now has 12. how many did he begin with?

Troyanec [42]

B=books
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Bought six more: b/2+
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3 years ago