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4 years ago

WHICH ONE !!!!!! HELPPPPP ASAP

Mathematics

2 answers:

lesantik [10]4 years ago

5 0

I think the answer is B

Troyanec [42]4 years ago

5 0

Usually when data goes down it decreases, it is a negative linear relationship. So the answer is B

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A triangle with side lengths 6in... 8in... and 10in plz oh plz help me. like right now

dezoksy [38]

6 x 10 = 60 x 8 = 480/2 = 240

8 0

3 years ago

Click an item in the list or group of pictures at the bottom of the problem and, holding the button down, drag it into the corre

Inessa05 [86]

Answer:

$3m^3-7m^2n+3mn^2-n^3$

Step-by-step explanation:

$(5m^3 + 3mn^2) + (-7m^2n + mn^2 - n^3) - (mn^2 + 2m^3)\\Solving:\\5m^3 + 3mn^2 -7m^2n + mn^2 - n^3 - mn^2 - 2m^3\\Adding\,\,like\,\,terms\,\,\\5m^3 -2m^3+ 3mn^2 -mn^2+mn^2-7m^2n-n^3\\3m^3 +3mn^2-7m^2n-n^3\\Arranging\,\,in\,\,desecnding\,\,order\,\,in\,\,power\,\,of\,\,m\\3m^3-7m^2n+3mn^2-n^3$

3 0

3 years ago

The cost per student of a ski trip varies inversely as the number of students who attend. It will cost each student $250 if 24 s

mars1129 [50]

ANSWER

30 students

EXPLANATION

The cost per student varies inversely as the number of students.

Inverse proportion is written as:

$\begin{gathered} y\propto\frac{1}{x} \\ y=\frac{k}{x} \\ \text{where k = constant of proportionality} \end{gathered}$

Let the cost per student be y.

Let the number of students be x.

It will cost each student $250 if 24 students attend. This means that:

$\begin{gathered} 250=\frac{k}{24} \\ \Rightarrow k=250\cdot24 \\ k=6000 \end{gathered}$

If the cost is down to $200, it means that y is now $200.

That is:

$\begin{gathered} 200=\frac{6000}{x} \\ \Rightarrow x=\frac{6000}{200} \\ x=30\text{ students} \end{gathered}$

Therefore, 30 students could attend.

5 0

2 years ago

Time spent using e-mail per session is normally distributed, with mu equals 11 minutes and sigma equals 3 minutes. Assume that

liq [111]

Answer:

a) 0.259

b) 0.297

c) 0.497

Step-by-step explanation:

To solve this problem, it is important to know the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are 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 random variable X, with mean $\mu$ and standard deviation $\sigma$ , a large sample size can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\mu = 11, \sigma = 3$

a. If you select a random sample of 25 sessions, what is the probability that the sample mean is between 10.8 and 11.2 minutes?

Here we have that $n = 25, s = \frac{3}{\sqrt{25}} = 0.6$

This probability is the pvalue of Z when X = 11.2 subtracted by the pvalue of Z when X = 10.8.

X = 11.2

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

By the Central Limit Theorem

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

$Z = \frac{11.2 - 11}{0.6}$

$Z = 0.33$

$Z = 0.33$ has a pvalue of 0.6293.

X = 10.8

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

$Z = \frac{10.8 - 11}{0.6}$

$Z = -0.33$

$Z = -0.33$ has a pvalue of 0.3707.

0.6293 - 0.3707 = 0.2586

0.259 probability, rounded to three decimal places.

b. If you select a random sample of 25 sessions, what is the probability that the sample mean is between 10.5 and 11 minutes?

Subtraction of the pvalue of Z when X = 11 subtracted by the pvalue of Z when X = 10.5. So

X = 11

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

$Z = \frac{11 - 11}{0.6}$

$Z = 0$

$Z = 0$ has a pvalue of 0.5.

X = 10.5

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

$Z = \frac{10.5 - 11}{0.6}$

$Z = -0.83$

$Z = -0.83$ has a pvalue of 0.2033.

0.5 - 0.2033 = 0.2967

0.297, rounded to three decimal places.

c. If you select a random sample of 100 sessions, what is the probability that the sample mean is between 10.8 and 11.2 minutes?

Here we have that $n = 100, s = \frac{3}{\sqrt{100}} = 0.3$

This probability is the pvalue of Z when X = 11.2 subtracted by the pvalue of Z when X = 10.8.

X = 11.2

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

By the Central Limit Theorem

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

$Z = \frac{11.2 - 11}{0.3}$

$Z = 0.67$

$Z = 0.67$ has a pvalue of 0.7486.

X = 10.8

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

$Z = \frac{10.8 - 11}{0.3}$

$Z = -0.67$

$Z = -0.67$ has a pvalue of 0.2514.

0.7486 - 0.2514 = 0.4972

0.497, rounded to three decimal places.

5 0

3 years ago

What is the sum of the series *picture attached*

Ksivusya [100]

Answer:

$\sum_{n=4}^{18}(n+1)^2=2440$

Step-by-step explanation:

Series: $\sum_{n=4}^{18} (n+1)^2$

Formula : $\sum_{k=m}^n=\sum_{k=1}^n-\sum_{k=1}^{m-1}$

$\Rightarrow \sum_{n=4}^{18}(n+1)^2=\sum_{n=1}^{18}(n+1)^2-\sum_{n=1}^{3}(n+1)^2$

$\sum_{n=1}^{18}(n+1)^2=2469$

$\sum_{n=1}^{3}(n+1)^2=29$

$\Rightarrow \sum_{n=4}^{18}(n+1)^2=2469-29$

$\Rightarrow \sum_{n=4}^{18}(n+1)^2=2440$

So, Option C is true

8 0

3 years ago