Answer:
Option d) Chebyshev's rule
Step-by-step explanation:
The Chebyshev's rule state that for a data that is not distributed normally,
atleast [tex](1 - \frac{1}{k^2})\% \text{ of data lies within the interval}~(Mean \pm (k)Standard ~Deviation)[/tex].
Here, k cannot be 1 and is always greater than 2.
For k = 2,
[tex](1 - \frac{1}{4})\times 100\% = 75\%[/tex] of data lies within the range of [tex](\mu \pm 2\sigma)[/tex]
Atleast 75% of children finished their vegetables in [tex](\mu \pm 2\sigma) = (4.2 \pm (2)1.0) = (2.2,6.2)[/tex]
For k = 3,
[tex](1 - \frac{1}{9})\times 100\% = 88.912\%[/tex] of data lies within the range of [tex](\mu \pm 3\sigma)[/tex]
Atleast 89% of children finished their vegetables in [tex](\mu \pm 3\sigma) = (4.2 \pm (3)1.0) = (1.2,7.2)[/tex]
Thus, option d) is correct.