how do the 4th grade girls weight in principal ben's school compare to the national mean weigh = 90 sd=15

Data lacking. What are the mean, standard deviation and n for the sample?

To compare the weight of 4th grade girls in Principal Ben's school to the national mean weight, we need to know the mean weight of 4th grade girls in Principal Ben's school and their standard deviation.

Once we have that information, we can use the concept of z-scores to compare weights. A z-score measures how many standard deviations a data point is away from the mean. It helps us standardize the data and compare it to a standard normal distribution.

To calculate the z-score, we will use the formula:

z = (x - μ) / σ

Where:
- x is the weight of the 4th grade girl in Principal Ben's school,
- μ is the mean weight of 4th grade girls in Principal Ben's school, and
- σ is the standard deviation of the weight of 4th grade girls in Principal Ben's school.

Once we calculate the z-score, we can interpret it in terms of the standard normal distribution. In a standard normal distribution, the mean is 0 and the standard deviation is 1. A positive z-score means the weight is above the mean, while a negative z-score means it is below the mean.

We can compare the z-score to find out whether the weight of 4th grade girls in Principal Ben's school is higher or lower compared to the national mean weight.