Ask question

Ask question

All categories

4 years ago

14

when u do a problem like this- 9+(-8) -does the -8 change to a positive 8 and does it become subtraction bc of the double negati

ve rule?

2 answers:

tekilochka [14]4 years ago

8 0

Changes to a positive

earnstyle [38]4 years ago

5 0

Correct, we were taught to change to sign to the opposite sign ex: 3+-1 would be 3-+1

You might be interested in

Suppose the slope of a line is positive. Describe what happens to the graph of the line as you move from left to right

creativ13 [48]

Since the slop of a line is positive, the graph of the line would begin to move upwards, rather than downwards. A graph line only moves downwards when the slope of the line is negative.

4 0

3 years ago

For exam!!!!!!!!!!!!!

Dvinal [7]

Answer:

Step-by-step explanation:

sheeeeeeesh

5 0

3 years ago

The mean weight of 10 randomly selected newborn babies at a local hospital is 7.14 lbs and the standard deviation is 0.87 lbs. A

sergejj [24]

Answer:

a) $ME= 1.83 \frac{0.87}{\sqrt{10}}=0.5035$

b) 90% of all samples of size 10 have sample means within 0.5035 of the population mean.

c) The 90% confidence interval would be given by (6.636;7.643)

d) Yes, since the lower limit for the 90% confidence interval is higher than the value of 6.5 we can conclude that the true mean is significantly higher than 6.5 at 10% of significance. (6.636>6.5)

e) If we increase the confidence level that implies increase the margin of error. Since with more confidence level the value for the critical value $t_{\alpha/2}$ increase. So then the new interval would be wider than the original.

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".

$\bar X=7.14$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

s=0.87 represent the sample standard deviation

n=10 represent the sample size

Part a

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

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

And the margin of error is given by:

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

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

$df=n-1=10-1=9$

Since the Confidence is 0.90 or 90%, the value of $\alpha=0.1$ 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: "=-T.INV(0.05,9)".And we see that $t_{\alpha/2}=1.83$

$ME= 1.83 \frac{0.87}{\sqrt{10}}=0.5035$

Part b

90% of all samples of size 10 have sample means within 0.5035 of the population mean.

Part c

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

$7.14-1.83\frac{0.87}{\sqrt{10}}=6.637$

$7.14+1.83\frac{0.87}{\sqrt{10}}=7.643$

So on this case the 90% confidence interval would be given by (6.636;7.643)

Part d

Yes, since the lower limit for the 90% confidence interval is higher than the value of 6.5 we can conclude that the true mean is significantly higher than 6.5 at 10% of significance. (6.636>6.5)

Part e

If we increase the confidence level that implies increase the margin of error. Since with more confidence level the value for the critical value $t_{\alpha/2}$ increase. So then the new interval would be wider than the original.

7 0

4 years ago

What is the graph of 5x+3y=13

hjlf

Answer:

See below

Step-by-step explanation:

5x+3y=13

3y=-5x+13

y=-5/3x+13/3

This graph has a slope of -5/3 and a y intercept of 13/3, as shown below. Hope this helps!

6 0

3 years ago

At party each guest receives five party favors. Write an expression that describes the total number of party favors bought if th

VladimirAG [237]

Answer:

<em>T</em> = 5<em>g</em> + 3

Step-by-step explanation:

The information provided is summarized as follows:

At party each guest receives five party favors
The variable "<em>g</em>" represent the number of guests.
Only three favors are left at the end.

Let <em>T</em> represent the total number of favors bought.

The expression representing the total number of favors given to the guests is:

5<em>g</em>.

Then the expression representing the total number of favors bought is:

<em>T</em> = 5<em>g</em> + 3

5 0

3 years ago