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3 years ago

I need the answer please and can u answer my recent to.

Mathematics

1 answer:

ale4655 [162]3 years ago

3 0

Answer:

30 hours.

Step-by-step explanation:

Richard can build 15 snowballs in 1 hour

But 2 snowballs melt every 15 minutes

In 1 hour, the number of snowballs that will have melted is:

$\frac{60}{15}$ × 2 = 8

The number of snowballs that will have remained = 15 - 8 = 7

So 7 snowballs will have remained in 1 hour

For 210 snowballs to have remained, it will take:

$\frac{210}{7}$ × 1 = 30 hours.

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'Ciumane ananen 32.50t + 5 = 28.75t + 20

gtnhenbr [62]

Answer:

The answer is 0.25

Step-by-step explanation:

(1)we group like terms by subtracting 32.50 by 28.75

(2) we subtract 20 and 5 to give us a value of 15

(3)when we subtract 32.50 and 28.75 we get a value of 3.75

(4)so the equation will look like this 3.75t = 15

(5)we divide 3.75 we both the two equations

(6)With a correct calculation, Your answer should be t = 0.25

6 0

3 years ago

Solve equation 3k+45=8k+25

Brrunno [24]

Answer:

k=4

Step-by-step explanation:

First, we can subtract 3k on both sides. It is ultimately easier to start by subtracting the term with a variable. This would result in 45=5k+25. Then, we can subtract 25 on both sides to get closer to isolating k. This becomes 20=5k. We can then divide by 5 on both sides. This means that k=4.

5 0

3 years ago

Read 2 more answers

A marketing researcher wants to find a 96% confidence interval for the mean amount those visitors spend per person per day while

ki77a [65]

Answer:

$n=(\frac{2.054(12)}{4})^2 =37.97 \approx 38$

So then the minimum sample to ensure the condition given is n= 38

Step-by-step explanation:

Notation

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=12$ represent the population standard deviation

n represent the sample size

ME = 4 the margin of error desired

Solution to the problem

When we create a confidence interval for the mean the margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =4 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 96% of confidence interval now can be founded using the normal distribution. The significance is $\alpha=1-0.96 =0.04$ . And in excel we can use this formula to find it:"=-NORM.INV(0.02;0;1)", and we got $z_{\alpha/2}=2.054$ , replacing into formula (b) we got: