Answer:
8r.
Step-by-step explanation:
If we substitute 3 into all of these equations, we get
8(3) which equals 24
6(3) which equals 18
9(3) which equals 27
7(3) which equals 21
8r is the one that equals 24 when 3 is substituted.
Answer:
The swimmer must complete the 200-meter backstroke in no more than 130 seconds.
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. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

Fastest 6%
At most in the 6th percentile, that is, at most a value of X when Z has a pvalue of 0.07. So we have to find X when Z = -1.555.




The swimmer must complete the 200-meter backstroke in no more than 130 seconds.
Answer:
816 people attended on Saturday night.
Step-by-step explanation: