Adult ticket (a) = $5
Child ticket (c) = $2
785 tickets = $3280
a + c = 785 tickets
5a + 2c = $3280
c = 215 child tickets
a = 570 adult tickets
570 + 215 = 785 tickets
5(570) + 2(215) = $3280
There were 215 child tickets sold on Saturday
Answer: in 95% of races, his finishing time will be between 62 and 64 seconds.
Step-by-step explanation:
The empirical rule states that for a normal distribution, nearly all of the data will fall within three standard deviations of the mean . The empirical rule is further illustrated below
68% of data falls within the first standard deviation from the mean.
95% fall within two standard deviations.
99.7% fall within three standard deviations.
From the information given, the mean is 63 seconds and the standard deviation is 5 seconds.
2 standard deviations = 2 × 0.5 = 1
63 - 1 = 62 seconds
63 + 1 = 64 seconds
Therefore, in 95% of races, his finishing time will be between 62 and 64 seconds.
