99.7 percentage of the data lies between 140 and 212 pounds when the distribution of the standard deviation is normal.
Any given quantity, which is used to express that how many observations differ from others in the total observations of a data, is referred to as standard deviation. It is represented by σ.
To calculate the percentage of data lying between the given values, we will use the formula of empirical method and the given information to compute as under,
[tex]\rm P(mu-3\ x\ \sigma < X < \mu + 3\ x\ \sigma)[/tex]
Solving further,
[tex]\rm P(176-3\ x\ \12 < X < \176+ 3\ x\ 12) = 0.997[/tex]
Hence, the significance upon the standard deviation of data weighted by Naomi is as aforementioned.
Learn more about standard deviation here:
https://brainly.com/question/16555520
#SPJ1