Ask question

Ask question

All categories

Zigmanuir [339]

3 years ago

12

A child standing 15 feet from the base of a lamppost casts a shadow 5 feet long. If the child is 4 feet tall and walks towards t

he lamppost at a speed of 10 feet per minute, at what rate, in feet per minute, will the length of his shadow be changing?

1 answer:

Ber [7]3 years ago

3 0

Step-by-step explanation:

Below is an attachment containing the solution.

You might be interested in

You have just used the network planning model and found the critical path length is 30 days and the variance of the critical pat

joja [24]

Answer:

0.726 is the probability that the project will be completed in 33 days or less.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 30 days

Variance = 25 days

Standard Deviation,

$\sigma = \sqrt{\text{Variance}} = \sqrt{25} = 5$

We assume that the distribution of path length is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

P(completed in 33 days or less)

$P( x \leq 33) = P( z \leq \displaystyle\frac{33 - 30}{5}) = P(z \leq 0.6)$

Calculation the value from standard normal z table, we have,

$P(x \leq 33) = 0.726 = 72.6\%$

0.726 is the probability that the project will be completed in 33 days or less.

8 0

2 years ago

What is the answer to this 8-(-8)=

Komok [63]

Answer:

16

Step-by-step explanation:

the two negatives cancel out so if you are subtracting -8 from 8 you would actually end up adding them.

hope it helps!

5 0

2 years ago

Read 2 more answers

In an examination of purchasing patterns of shoppers, a sample of 16 shoppers revealed that they spent, on average, $54 per hour

Lesechka [4]

Answer:

$54-1.64\frac{21}{\sqrt{16}}=45.39$

$54 +1.64\frac{21}{\sqrt{16}}=62.61$

So on this case the 90% confidence interval would be given by (45.39;62.61)

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".

$\bar X=54$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=21$ represent the sample standard deviation

n=16 represent the sample size

Solution to the problem

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 0.90 or 90%, the value of $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that $z_{\alpha/2}=1.64$

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

$54-1.64\frac{21}{\sqrt{16}}=45.39$

$54 +1.64\frac{21}{\sqrt{16}}=62.61$

So on this case the 90% confidence interval would be given by (45.39;62.61)

4 0

3 years ago

PLEASE HALP I GIVE OUT BRAINLIEST

jekas [21]

Since there is two negative signs in the original equation, you need two negative signs in the equivalent one as well.

Because one of the negatives if before the fraction, it doesn't matter if the second negative is on the 13 or on the 12.

The answer is A.

4 0

2 years ago

Read 2 more answers

HELP HELP HELP 6 = x/8<br><br> The question is what is "x"?

german

Answer:

x= 48

Step-by-step explanation:

Multiply 8 by 6 to get x by itself and you get your answer.

5 0

3 years ago

Read 2 more answers