AC = 8.9
BC = 6.5
(90% angle)
8.9 x 6.5 = <span>57.85
57.85/2 = 28.925
Area of ^ABC = 28.925 cm squared

DE = 55.1
55.1/ 11.02 = 5
DEF is 5 times as big as ABC
DF = 44.5
FE = 32.5
44.5 x 32.5 = 1446.25
1446.25/2 = 723.125
I am not positive but I believe DEF = 723.125 cm squared
Good Luck on the Test!! :D

</span>

7 0

4 years ago

Sample size: A researcher is trying to decide how many people to survey. Which of the following sample sizes will result in a co

oksian1 [2.3K]

Answer:

Step-by-step explanation:

Given that a researcher is trying to decide how many people to survey.

We have confidence intervals are intervals with middle value as the mean and on either side margin of error.

Confidence interval = Mean ± Margin of error

Thus confidence interval width depends on margin of error.

Margin of error = $Critical value *\frac{\sigma}{\sqrt{n} }$

Thus for the same confidence level and std deviation we find margin of error is inversely proportional to square root of sample size.

Hence for small n we get wide intervals.

So if sample size = 300, the researcher will get wider confidence interval

4 0

4 years ago

Find the length of side x in simplest radical form with rational denominator.

DaniilM [7]

Answer:

sqrt(20)

Step-by-step explanation:

The two perpendicular side lengths are equal, so using Pythagoras theorem:

x = sqrt( sqrt(10)^2 + sqrt(10)^2 )

x = sqrt(10 + 10)

x = sqrt(20)

8 0

3 years ago