Sophie earns $7 an hour babysitting and $8 an hour for cleaning the house last week she babysat for 3 hours and clean for 2 hour
1 answer:
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Answer:
D. 0.9938.
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation
, the z-score of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean of 115 and a standard deviation of 8.
This means that
100 people are randomly selected
This means that
Find the probability that their mean blood pressure will be less than 117.
This is the p-value of Z when X = 117, so:
By the Central Limit Theorem
has a p-value of 0.9938, and thus, the correct answer is given by option D.
For any right triangle, we can use the Pythagorean Theorem. The Pythagorean Theorem states that for any right triangle, the legs when squared and added together will be equal to the hypotenuse squared.
In mathematical notation:
Where the variables a and b are the legs and the variable c is the hypotenuse.
Because we know the two side lengths of the triangle, we can solve for the unknown side.
We know the length of one of the legs and the hypotenuse.
Plug in the values.
So, the square root of 476 is the unknown length.
In mathematical notation:
Where the variables a and b are the legs and the variable c is the hypotenuse.
Because we know the two side lengths of the triangle, we can solve for the unknown side.
We know the length of one of the legs and the hypotenuse.
Plug in the values.
So, the square root of 476 is the unknown length.