Hi,
The answer is c. The sample is biased.
This is because the sample is taken on a single state, an Rebecca reports a statistic about the nation. Her data contains information only of her state. If she lives in a very cold state, there is probably more homeowners using electric heat than in a hot state.
I don’t really get your question, because you said that ¾ of them are girls, Then how many girls are working in the piano?
You did not stated the question well.
However, I will try to answer this base on my understanding.
There are a total of 12 students that works in the library.
IF ¾ of them are girls:
=> 12 / 4 = 3 *3 = 9
=> 9 of them are girls and 3 of them are boys.
Thus, how many girls are working in the piano.
The probability is 9, there might be 9 girls working in the piano, or less than 9. Since you did not mention how many girls worked in different part of the library.
Answer:
Step-by-step explanation:
The set of all integer numbers
Answer: 0. 74
Step-by-step explanation: 31/42= 0.738095238095= 0.74
Answer:
Work done in stretching the spring = 7.56 lb-ft.
Step-by-step explanation:
Normal length of the spring = 8 in or
ft
=
ft
If the spring has been stretched to 11 inch then the stretched length of the spring is = 11 in
=
ft
Force applied to stretch the spring = 12 lb
By Hook's law,
F = kx [where k is the spring constant and x = length by which the spring is stretched]
12 = k(
)
k = 18
Work done (W) to stretch the spring by
ft will be
W = ![\int\limits^\frac{11}{12} _0 {kx} \, dx](https://tex.z-dn.net/?f=%5Cint%5Climits%5E%5Cfrac%7B11%7D%7B12%7D%20_0%20%7Bkx%7D%20%5C%2C%20dx)
= ![\int\limits^\frac{11}{12} _0 {(18x)} \, dx](https://tex.z-dn.net/?f=%5Cint%5Climits%5E%5Cfrac%7B11%7D%7B12%7D%20_0%20%7B%2818x%29%7D%20%5C%2C%20dx)
= ![18[\frac{x^{2}}{2}]^{\frac{11}{12}}_0](https://tex.z-dn.net/?f=18%5B%5Cfrac%7Bx%5E%7B2%7D%7D%7B2%7D%5D%5E%7B%5Cfrac%7B11%7D%7B12%7D%7D_0)
= 9(
)²
= 7.56 lb-ft