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3 years ago

Bobby hopes that he will someday be more than 70 inches tall. he is currently 61 inches tall. how many more inches,

1 answer:

4 0

Bobby should grow an amount greater than 70-61 = 9 inches to become taller than 70 inches. Therefore, the correct answer is that Bobby must grow an amount of x> 9 inches to be taller than 70 inches.

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Maya is M years old which expression shows how old she will be in four years from now

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Your answer would be x=m×4

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3 years ago

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How many times does 23 go into 194?

USPshnik [31]

The answer is approximately 0.11857

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2 years ago

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The length of overline CD is 12 units. C^ prime D^ prime is the image of overline CD under a dilation with a scale factor of n.

Rufina [12.5K]

Answer:

A, D , and E

Step-by-step explanation:

We have that:

$\overline{CD} = 12 \: units$

$\overline{C'D'}$

is the image of CD after a dilation of scale factor n.

We use the relation between the image length and object length:

$\overline{C'D'} = n \times \overline{CD}$

Option A

If n=3/2, then

$\overline{C'D'} = \frac{3}{2} \times 12 = 3 \times 6 = 18 \: units$

This is true.

Option B

If n=4, then

$\overline{C'D'} = 4 \times 12 = 36 \: units$

This is false.

Option C

If n=8, then

$\overline{C'D'} = 8 \times 12 = 96 \: units$

This too is false.

Option D

If n=2, then

$\overline{C'D'} = 2 \times 12 = 24 \: units$

This is true

Option E

If n=3/4, then

$\overline{C'D'} = \frac{3}{4} \times 12$

$\overline{C'D'} = 3 \times 3 = 9 \: units$

This is also true.

4 0

3 years ago

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

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".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

Now we have everything in order to replace into formula (1):

$21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

Part b

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{350}}=7.17$

Part c

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{100}}=13.42$

Part d

As we can see when we reduce the sample size we increase the margin of error so the best option for this case is:

D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

6 0

2 years ago

The graph from the US Department of Agriculture shows the growth of farmers markets in the United States. What was the first yea

Helen [10]

The answer is C.) 2002
The graph shows that the previous years have been under that, the number of markets is shown on the y axis

3 0

3 years ago