<span>A midpoint divides a line or a segment into two equal parts. If D is the midpoint of the segment AC and C is the midpoint of segment DB, what is the length of the segment AB, if AC = 3 cm.</span>

If D is the midpoint of AC, then AD=DC

If C is the midpoint of DB, then DC=CB

If AC=3cm. then then DC-3/2=1.5

If DC=1.5 then CB is 1.5 also

AB=AC+CB

AB=3+1.5

AB=4.5

5 0

2 years ago

NEED HELP!! PLEASE PLEASE

Bezzdna [24]

Answer:

The answer is A

Step-by-step explanation:

hope this helps,

If you like my answer please give brainliest,

Happy Holidays!

6 0

2 years ago

In a recent study of 42 eighth graders, the mean number of hours per week that they watched television was 19.6. Assume the popu

olya-2409 [2.1K]

Answer:

$19.6-2.42\frac{5.8}{\sqrt{42}}=17.43$

$19.6+2.42\frac{5.8}{\sqrt{42}}=21.77$

And the best option for this case would be:

a. (17.5, 21.7)

Step-by-step explanation:

Information given

$\bar X= 19.6$ represent the sample mean

$\mu$ population mean

$\sigma= 5.8$ represent the population deviation

n=42 represent the sample size

Confidence interval

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

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

The degrees of freedom, given by:

$df=n-1=42-1=41$

Since the Confidence is 0.98 or 98%, the significance would be $\alpha=0.02$ and $\alpha/2 =0.1$ , and the critical value would be $t_{\alpha/2}=2.42$

Replacing we got:

$19.6-2.42\frac{5.8}{\sqrt{42}}=17.43$

$19.6+2.42\frac{5.8}{\sqrt{42}}=21.77$

And the best option for this case would be:

a. (17.5, 21.7)

8 0

3 years ago