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2 years ago

Help meeee with this questionnnnnnnnnn!!!!!!!!!!!!

Mathematics

1 answer:

Dafna1 [17]2 years ago

3 0

Given:

The scale factor between two circles is $\dfrac{2x}{5y}$ .

To find:

The ratio of their areas.

Solution:

We know that, all circles are similar.

The ratio of the areas of similar figures is equal to the ratio of squares of their corresponding sides or equal to the square of ratio of their corresponding sides.

The scale factor is the ratio of the corresponding sides.

Ratio of areas of circles = Square of scale factor between two circles

$\text{Ratio of areas of circles}=\left(\dfrac{2x}{5y}\right)^2$

$\text{Ratio of areas of circles}=\dfrac{(2x)^2}{(5y)^2}$

$\text{Ratio of areas of circles}=\dfrac{4x^2}{25y^2}$

Therefore, the correct option is D.

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Jumbo eggs in Australia, on average, are supposed to weigh 68g. Margot is in charge of a quality control test that involves weig

Andrej [43]

Answer:

0.9987 = 99.87% probability that the mean weight of 4 eggs in a package is less than 68.5g

Step-by-step explanation:

To solve this question, we use the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean weight of 67g and a sample standard deviation of 1g.

This means that $\mu = 67, \sigma = 1$

Sample of 4

This means that $n = 4, s = \frac{1}{\sqrt{4}} = 0.5$

What is the probability that the mean weight of 4 eggs in a package is less than 68.5g?

This is the pvalue of Z when X = 68.5. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{68.5 - 67}{0.5}$

$Z = 3$

$Z = 3$ has a pvalue of 0.9987

0.9987 = 99.87% probability that the mean weight of 4 eggs in a package is less than 68.5g

6 0

2 years ago

Read 2 more answers

Help me pleaseeeeeee?

BlackZzzverrR [31]

Answer:

-7x+3y+3

Step-by-step explanation:

(4-5+4)=3

(-2x-5x)=-7x

(-4y+7y)=3y

6 0

3 years ago

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Given

kondaur [170]

Answer:

+ 10 and + 7

Step-by-step explanation:

Given

2x² + 7x + 5

Consider the factors of the product of the coefficient of the x² term and the constant term which sum to give the coefficient of the x- term.

product = 2 × 5 = + 10 and sum = + 7

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2 years ago

An economist conducted a study of the possible association between weekly income and weekly grocery expenditures. The particular

kolezko [41]

Answer:

42.1% of variation in the response is explained by the regression line

Step-by-step explanation:

Correlation coefficient is a measure which tells us that how strongly are two variables under study are linearly related to each other i.e correlation coefficient gives the strength of linear association between the variables.

If the magnitude of correlation coefficient is closer to 1, it indicates a strong linear relationship. If the magnitude of correlation coefficient is closer to 0, it indicates a weak linear relationship.

There is another variable known as "Coefficient of Determination", which is equal to square of Correlation Coefficient. Coefficient of Determination tells us that what percentage of variation in the response of the study can be explained by the regression line.

This means, for this question we need to calculate the Coefficient of Determination.

Correlation coefficient = r = 0.649

Coefficient of Determination = R = r² = (0.649)²= 0.421 = 42.1 %

This means that 42.1% of variation in the response is explained by the regression line.

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2 years ago

What’s does 2+2 evaluation to

topjm [15]

Answer:4

Step-by-step explanation:

2+2 = 4

Adding 2 in 2 gives us 4.

4 0

3 years ago