Help please, I don’t know what to do..
1 answer:
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Answer:
The travel time that separates the top 2.5% of the travel times from the rest is of 91.76 seconds.
Step-by-step explanation:
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.
Mean of 80 seconds and a standard deviation of 6 seconds.
This means that
What travel time separates the top 2.5% of the travel times from the rest?
This is the 100 - 2.5 = 97.5th percentile, which is X when Z has a p-value of 0.975, so X when Z = 1.96.
The travel time that separates the top 2.5% of the travel times from the rest is of 91.76 seconds.
Answer:
The theater has 32 rows
Step-by-step explanation:
The rule of the sum of n terms of an arithmetic sequence is S =
(a + l), where
- a is the first term
- l is the last term
- n is the number of the terms
∵ The number of seats per row follows an arithmetic sequence
∵ The first row has 26 seats
∴ a = 26
∵ The last row has 150 seats
∴ l = 150
∵ The theater seats are 2,816
∴ S = 2,816
→ Substitute these values in the rule of the sum above to find n
∵ 2,816 = (26 + 150)
∴ 2,816 = (176)
∴ 2,816 = 88n
→ Divide both sides by 88
∴ 32 = n
∵ n represents the number of the rows
∴ The theater has 32 rows