Sam and Lilly own a condominium where they paid $2950 in maintenance fees this year. If her property taxes are 18% of this amoun
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Answer:
b. the area to the right of 2
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean and standard deviation
, the zscore 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, which is also the area to the left of Z. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X, which is the area to the right of Z.
In this problem:
Percentage who did better:
P(Z > 2), which is the area to the right of 2.
Answer:
Sarah is 13 years old
Step-by-step explanation:
Represent Sarah's age with S
Her first brother's age with F
Her second brother's age with B
So, we have:
From the first statement, we have:
---- (1)
From the second, we have:
---- (2)
The product of their ages is 40.
First, we make F the subject in (1) and B the subject in (2)
Their product is represented as follows:
Substitute values for F and B
Open bracket
Subtract 40 from both sides
Factorize:
Split:
or
But Sarah's age can't be 0 because she has two younger brothers.
So, we stick to
Make S the subject
<em>Hence, Sarah is 13 years old</em>