The line plot shows it increases
x + 47 = 92. <--- x represents the number of 3rd graders
x +47-47 = 92-47
x=45
There are 45 third grader. Hope this helped!
To obtain an estimate of a parameter of a population, we use confidence intervals.
Confidence intervals:
The larger the sample size, the closest the parameter estimate is to the value of the population, as the margin of error of confidence intervals is inversely proportional to the sample size, that is, a greater sample leads to a smaller margin of error.
Thus, you should select the highest sample size in the options.
For more on confidence interval/margin of error, you can check brainly.com/question/22718960
The answers to the first two systems of equations
1. H+S=40
2. 19H+25S=922
From 1,
19H+19S=760
Subtract this from 2 to eliminate H,
19H+25S-19H-19S=922-760
6S=162
Solve for S, then use either equation to solve for H.