I am confused and i dont know how i would do this

Complete the following statement.<br><br> 5 - ( ) = 14

Paha777 [63]

Answer:

19

Step-by-step explanation:

you would choose a number that you can easily subtract 5 from. You should always take care of whats in the () first.

7 0

3 years ago

Read 2 more answers

Which expression is equal?

mars1129 [50]

Answer:

the first option

if you simplified the expression it would be 2l+2w+8a

4 0

3 years ago

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18 2/5 - n = -10 1/3

Wewaii [24]

Answer:

The answer is $n=28\frac{11}{15}$ .

Step-by-step explanation:

Given:

18 2/5 - n = -10 1/3.

Now, to solve the equation:

$18\frac{2}{5} - n = -10 \frac{1}{3}$

Converting the mixed fractions to improper:

⇒ $\frac{92}{5} -n=-\frac{31}{3}$

Moving the numbers on one side and variable to the other:

⇒ $\frac{92}{5} +\frac{31}{3}=n$

Now, solving the factions:

⇒ $\frac{92\times 3+31\times 5}{15}=n$

⇒ $\frac{276+155}{15}=n$

⇒ $\frac{431}{15}=n$

⇒ $28\frac{11}{15}=n$

Therefore, the answer is $n=28\frac{11}{15}$ .

3 0

4 years ago

The time (in number of days) until maturity of a certain variety of tomato plant is normally distributed with mean µ and standar

tino4ka555 [31]

Answer:

a) $63.5-2.58\frac{2.4}{\sqrt{4}}=60.404$

$63.5+2.58\frac{2.4}{\sqrt{4}}=66.596$

So on this case the 99% confidence interval would be given by (60.404;66.596)

b) $n=(\frac{2.58(2.4)}{1})^2 =38.34 \approx 39$

So the answer for this case would be n=39 rounded up to the nearest integer

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".

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

$\mu$ population mean (variable of interest)

s represent the sample standard deviation

n represent the sample size

Part a

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

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

In order to calculate the mean we can use the following formula:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

The mean calculated for this case is $\bar X=63.5$

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):

$63.5-2.58\frac{2.4}{\sqrt{4}}=60.404$

$63.5+2.58\frac{2.4}{\sqrt{4}}=66.596$

So on this case the 99% confidence interval would be given by (60.404;66.596)

Part b

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 =1 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 99% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.005;0;1)", and we got $z_{\alpha/2}=2.58$ , replacing into formula (b) we got:

$n=(\frac{2.58(2.4)}{1})^2 =38.34 \approx 39$

So the answer for this case would be n=39 rounded up to the nearest integer

5 0

3 years ago

Please help me please, please, please

yaroslaw [1]

Answer:

23.3%

Step-by-step explanation:

Wow, that's definitely a confusing way to teach it. Let me help you understand it:

7 is what percent of 30? This is:

7 / 30 or $\frac{7}{30}$

We are going to do cross multiplication to find the missing value, X.

$\frac{x}{100} =\frac{7}{30}$

30 * X = 100 * 7

30X = 700

X = $\frac{700}{30}$

X = 23.3 % is the missing value

3 0

3 years ago