At Riptide Roller Coaster Park, 55% of those surveyed named the Super Loop as their favorite ride. If 1,100 people chose the Sup
2 answers:
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Answer:
8.85% probability that fewer than 82 accounts in the sample were at least 1 month in arrears
Step-by-step explanation:
For each account, there are only two possible outcomes. Either they are at least 1 month in arrears, or they are not. The probability of an account being at least 1 month in arrears is independent from other accounts. So the binomial probability distribution is used to solve this question.
However, we are working with a large sample. So i am going to aproximate this binomial distribution to the normal.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
Can be approximated to a normal distribution, using the expected value and the standard deviation.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
Normal probability distribution
Problems of normally distributed samples can be 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. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
When we are approximating a binomial distribution to a normal one, we have that ,
.
In this problem, we have that:
So
What is the probability that fewer than 82 accounts in the sample were at least 1 month in arrears
This probability is the pvalue of Z when X = 82. So
has a pvalue of 0.0885.
8.85% probability that fewer than 82 accounts in the sample were at least 1 month in arrears
Answer: The correct option is
(A) The measures of corresponding angles of ABCD and KLMN are equal, but the lengths of corresponding sides of ABCD are half those of KLMN.
Step-by-step explanation: We are given to select the correct condition that might be true if polygons ABCD and KLMN are similar.
Two polygons are said to be SIMILAR if corresponding angles are congruent and corresponding sides are proportional.
So, options (B), (C), (D) and (E) are not correct because they contradict conditions of similarity.
In option (A), we have
The measures of corresponding angles of ABCD and KLMN are equal. So, they must be congruent.
And the lengths of corresponding sides of ABCD are half those of KLMN.
So, we can write
Therefore, the corresponding sides are proportional.
Thus, option (A) is true if two polygons are similar.