Twice the sum of x and y decreased by 21
1 answer:
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Answer:
Step-by-step explanation:
Assuming this complete question:
"Suppose a certain species of fawns between 1 and 5 months old have a body weight that is approximately normally distributed with mean kilograms and standard deviation
kilograms. Let x be the weight of a fawn in kilograms. Convert the following z interval to a x interval.
"
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
Let X the random variable that represent the weights of a population, and for this case we know the distribution for X is given by:
Where and
And the best way to solve this problem is using the normal standard distribution and the z score given by:
We know that the Z scale and the normal distribution are equivalent since the Z scales is a linear transformation of the normal distribution.
We can convert the corresponding z score for x=42.6 like this:
So then the corresponding z scale would be:
Answer:
Step-by-step explanation:
Multiply the equations together
(5x+4)(5x^2-7x-2)
25x^3-35x^2-10x+20x^2-28x-8
Add like terms
25x^3-15x^2-38x-8