3. ΔBDE ~ ΔBCF
4. BF/BC = BE/BD
5. 254/BC = 160/457
.. BC = 254*457/160 ≈ 725 units
Answer:
[B] A two-sample t -test for a difference between means.
Step-by-step explanation:
"<u>A two sample t test for a difference in means was conducted to investigate whether the average time to swim a lap with the freestyle stroke is different from the average time to swim a lap with the butterfly stroke</u>."
Answer: It will take 
of an hour to complete the test.
Step-by-step explanation:
We need to convert the mixed number 
to an improper fraction:
Now, we need to make the following add the fractions in order to calculate how many hours will it take to complete the test. Then, we get:
Therefore, it will take of an hour to complete the test.
Distribute the two to each of the values in the parentheses.
-4 +6a-10= 1-1a
Then move like terms to the same side to simplify.
6a+1a=1+10+4
7a=15
a=15/7
