All categories

3 years ago

Explain how a(b + c ) can rewritten as (b + c) and as ba + ca

Mathematics

1 answer:

mart [117]3 years ago

5 0

Answer:

The distributive property makes it possible

Step-by-step explanation:

Step one:

given the expression a(b + c )

the first step is to open the bracket, that is multiply all the terms in the bracket by a, so multiply b by a and c by a also.

Step two:

Thus, this property is called the distributive property of multiplication

a*b+ca

You might be interested in

What is the rate of change between the points (-3, 0) and (-2, -5)?

Elis [28]

The rate of change is the change in Y over the change in X.

Rate of change = (-5 - 0) / (-2 - -3)

Rate of change = (-5 ) / (-2+3)

Rate of change = -5 /1

Rate of change = -5

3 0

3 years ago

In a random sample of 25 people, the mean commute time to work was 33.9 minutes and the standard deviation was 7.2 minutes. Ass

Phoenix [80]

Answer:

$33.9-1.32\frac{7.2}{\sqrt{25}}=31.999$

$33.9+1.32\frac{7.2}{\sqrt{25}}=35.801$

So on this case the 80% confidence interval would be given by (31.999;35.801)

And the margin of error is given by:

$ME = t_{\alpha/2}\frac{s}{\sqrt{n}}$

And replacing we got:

$ME = 1.32\frac{7.2}{\sqrt{25}} =1.9008$

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".

$\bar X=33.9$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=7.2 represent the sample standard deviation

n=25 represent the sample size

Solution to the problem

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

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

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=25-1=24$

Since the Confidence is 0.80 or 80%, the value of $\alpha=0.2$ and $\alpha/2 =0.1$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.01,24)".And we see that $t_{\alpha/2}=1.32$

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

$33.9-1.32\frac{7.2}{\sqrt{25}}=31.999$

$33.9+1.32\frac{7.2}{\sqrt{25}}=35.801$

So on this case the 80% confidence interval would be given by (31.999;35.801)

And the margin of error is given by:

$ME = t_{\alpha/2}\frac{s}{\sqrt{n}}$

And replacing we got:

$ME = 1.32\frac{7.2}{\sqrt{25}} =1.9008$

7 0

4 years ago

Let f(t)=6−2t2. Evaluate f(t+1).

tia_tia [17]

Answer:

f(t+1)= -4t+2

Step-by-step explanation:

Subsitute the given vaule into the function and evaluate.

7 0

3 years ago

Olivia needs 54 licks for every 3 lollipop she licks

Lesechka [4]

Answer:

PLEASE BUY ME BITEABLE ACCOUNT. COSTS 19 DOLLARS! PLEASE ANYONE!

Step-by-step explanation:

To find how many licks she does to 1 lollipop, 54 divided by 3 which is 18. So, 18 licks/lollipop. 36/18=2. Which means Olivia licks 2 lollipops in 36 licks. To find 5 lollipops, 18*5=90. She licks 5 lollipops in 90 licks.

8 0

4 years ago

baherus [9]

Answer:

there are 8 students for each computer

Step-by-step explanation:

7 0

4 years ago