The mean weight is 89 kgs.
[tex]Arithmetic mean = \frac{Sum Of All Terms}{Total Number Of Terms}[/tex]
Given:
=> Total weight of 9 people = 79 [tex]\times[/tex] 9 = 711kg.
Let the weight of 10th person be x.
Then, according to question,
[tex]Mean Weight Of 10 People = \frac{Total Weight Of 10 People}{10}[/tex]
=> [tex]Mean Weight Of 10 People = \frac{711+x}{10} = 79+1=80[/tex]
=> [tex]711+x= 80\times10[/tex]
=> x = 800 - 711 = 89
That is, the 10th person weighs 89kg.
To learn more about arithmetic mean, refer to the given link:
https://brainly.com/question/20118982
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