Answer:
165m
Question:
Artur, Olga and Wiktor participated in the race. They started from the same place at the same time and run at constant speeds. When Artur finished the race, Olga was 15 m to the finish,
and Wiktor was 35 m. When Olga finished the race, Wiktor remained 22 m to the finish. At what distance was the race held?
Step-by-step explanation:
Let Artur distance covered be =>x
When Artur covered distance x:
Olga was 15m from x
Olga = x - 15
Wiktor was 35m from x
Wiktor = x - 35
When Olga covered distance x:
Wiktor was 22m from x
The ratio of Olga to Wiktor:
(x-15)/(x-35) = x/(x-22)
Cross multiply
(x-15)(x-22) = x(x-35)
x² - 15x - 22x + 330 = x² - 35x
x² -37x +330 - x² + 35x = 0
-2x = -330
x = (-330)/(-2)
x = 165m
The race held at 165m distance
Answer:
At least 75% of the observations lie between 16 and 28.
Step-by-step explanation:
The Chebyshev’s Theorem says:
For any numerical data set, at least of the data lie within k standard deviations of the mean, that is, in the interval with endpoints for populations, where k is any positive whole number that is greater than 1.
Given:
The interval (16, 28) is the one that is formed by adding and subtracting two standard deviations from the mean.
For k = 2, we see that , which is 75% of the data must always be within two standard deviations of the mean.
At least 75% of the observations lie between 16 and 28.
(Answer 2,770) (estimation: 3,000)