Answer:
Step-by-step explanation:
To start calculating, we first need to make some proof.
Firstly, since AB = AC, we know that ΔABC is isosceles, which means that ∠ABC = ∠ACB.
Now, looking only to ΔBDE and ΔCDF, we can see that they are similar, because the two of its angles are congruent:
∠BED=∠CFD
∠DBE=∠DCF
To make it easier to visualize which are the corresponding vertexes, we can draw them like this:
And we need to remember that BC is 24, so:
BD+CD=24
Since the triangles are similar, their corresponding sides have constant ratio, which we can calculate from the corresponding sides DE and CF:

This ratio is the same for the other corresponding sides, so we can apply that for BD and CD:

Thus, the measure of CF is approximately 13, alternative D.
Answer:
The naswer to your question is: letter c)70
Step-by-step explanation:
Data
2 skeins of yarn cost $7
8 skeins of yarn cost $28
total = 20 skeins
cost = ?
Equation = she need s to buy 2 skeins of 8 a 2 skeins of 2
cost = 2 x $28 + 2 X $7
cost = 56 + 14
cost = $70
Complete Question
The complete question is shown on the first uploaded image
Answer:
The interval is 
Step-by-step explanation:
From the question we are told that
The first sample size is 
The first sample proportion is 
The second sample size is 
The second sample proportion is 
Given that the confidence level is 95% then the level of significance is mathematically evaluated as


Next we obtain the critical value of
from the normal distribution table
The value is

Generally the 95% confidence interval is mathematically represented as

Here
is mathematically evaluated as 
and
is mathematically evaluated as 
So

