Can someone help please?
2 answers:
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Answer:
The standard deviation of weight for this species of cockroaches is 4.62.
Step-by-step explanation:
Given : A different species of cockroach has weights that are approximately Normally distributed with a mean of 50 grams. After measuring the weights of many of these cockroaches, a lab assistant reports that 14% of the cockroaches weigh more than 55 grams.
To find : What is the approximate standard deviation of weight for this species of cockroaches?
Solution :
We have given,
Mean
The sample mean x=55
A lab assistant reports that 14% of the cockroaches weigh more than 55 grams.
i.e. P(X>55)=14%=0.14
The total probability needs to sum up to 1,
The z-score value of 0.86 using z-score table is z=1.08.
Applying z-score formula,
Where, is standard deviation
Substitute the values,
The standard deviation of weight for this species of cockroaches is 4.62.
Answer:
The function is defined when x > 0
Step-by-step explanation:
Functions with radicals are only undefined when the value in the radical is negative, because the root of a negative number is imaginary.
We know the function is undefined when the denominator is equal to zero. is equal to zero when x=0.
We also know that functions with radicals are undefined when the value in the radicals are negative, because the root of a negative number is imaginary. . will always be positive, but
is negative when x < 0.
So the function is undefined when x = 0, and when x < 0.
Therefore it is defined when x > 0