Answer:
25 hours
Step-by-step explanation:
Answer: The value of y=9.
The temperature went down by 12 degrees. (Or you could say it changed by -12 degrees)
Answer:

And for this case we know this condition:

By the complement rule we know that:

But since the distribution is symmetrical we know that:

So then the statement for this case is FALSE.
b. False
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
For this case if we define the random variable of interest X and we know that this random variable follows a normal distribution:

And for this case we know this condition:

By the complement rule we know that:

But since the distribution is symmetrical we know that:

So then the statement for this case is FALSE.
b. False
Answer:
![\boxed{ \frac{ \sqrt[3]{ {x}^{11} } }{4} }](https://tex.z-dn.net/?f=%20%5Cboxed%7B%20%20%5Cfrac%7B%20%5Csqrt%5B3%5D%7B%20%7Bx%7D%5E%7B11%7D%20%7D%20%7D%7B4%7D%20%7D%20)
Step-by-step explanation:
![= > \frac{ {x}^{4} }{ \sqrt[3]{64x} } \\ \\ = > \frac{ {x}^{4} }{ {(64x)}^{ \frac{1}{3} } } \\ \\ = > \frac{ {x}^{4} }{ ({64}^{ \frac{1}{3} } )\times ({x}^{ \frac{1}{3} } )} \\ \\ = > \frac{ {x}^{4} }{ ({( {4}^{3} )}^{ \frac{1}{3} }) \times( {x}^{ \frac{1}{3} } )} \\ \\ = > \frac{ {x}^{4} }{ ({4}^{ \cancel{3} \times \frac{1}{ \cancel{3}} } ) \times( {x}^{ \frac{1}{3} } )} \\ \\ = > \frac{ {x}^{4} }{4 {x}^{ \frac{1}{3} } } \\ \\ = > \frac{ {x}^{4 - \frac{1}{3} } }{4} \\ \\ = > \frac{ {x}^{ \frac{12 - 1}{3} } }{4} \\ \\ = > \frac{ {x}^{ \frac{11}{3} } }{4} \\ \\ = > \frac{ \sqrt[3]{ {x}^{11} } }{4}](https://tex.z-dn.net/?f=%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%7D%20%7D%7B%20%5Csqrt%5B3%5D%7B64x%7D%20%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%7D%20%7D%7B%20%7B%2864x%29%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%7D%20%7D%7B%20%28%7B64%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%20%29%5Ctimes%20%20%28%7Bx%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%29%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%7D%20%7D%7B%20%28%7B%28%20%7B4%7D%5E%7B3%7D%20%29%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%29%20%5Ctimes%28%20%20%7Bx%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%20%29%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%7D%20%7D%7B%20%28%7B4%7D%5E%7B%20%5Ccancel%7B3%7D%20%5Ctimes%20%20%5Cfrac%7B1%7D%7B%20%5Ccancel%7B3%7D%7D%20%7D%20%29%20%5Ctimes%28%20%20%7Bx%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%20%29%7D%20%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%7D%20%7D%7B4%20%7Bx%7D%5E%7B%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B4%20-%20%20%5Cfrac%7B1%7D%7B3%7D%20%7D%20%7D%7B4%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B%20%5Cfrac%7B12%20-%201%7D%7B3%7D%20%7D%20%7D%7B4%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%5Cfrac%7B%20%7Bx%7D%5E%7B%20%5Cfrac%7B11%7D%7B3%7D%20%7D%20%7D%7B4%7D%20%20%5C%5C%20%20%5C%5C%20%20%3D%20%20%3E%20%20%20%5Cfrac%7B%20%5Csqrt%5B3%5D%7B%20%7Bx%7D%5E%7B11%7D%20%7D%20%7D%7B4%7D%20)