## Using PX5 Lesson 10

In this lesson, you will study some adjustment theory, especially as related to the statistics of least squares adjustments.

Please carefully study all details of the following document: Basic Adjustment Statistics.

After you are comfortable with the content of the above document, please answer the following questions:

Once you have answered all of the above questions, please email your answers to me. Thank you.

Please carefully study all details of the following document: Basic Adjustment Statistics.

After you are comfortable with the content of the above document, please answer the following questions:

- Why do we say that the standard calculation of the average value and standard deviation is actually a least squares adjustment?
- When analyzing the misclosures in an adjustment, why must we ensure that our initial values of the parameters are sufficiently accurate?
- When analyzing the standardized residuals in an adjustment, what is the acceptable statistical range for each standardized residual?
- Under which conditions is it acceptable to leave a measurement in our adjustment, even when its standardized residual is flagged for rejection?
- Why is it acceptable to scale the measurement variances by the estimated variance factor, even when that variance factor is relatively large?
- Why must we remove only one measurement at a time when it has the largest flagged standardized residual?
- What is the procedure for estimating the actual accuracy of the measurements in our least squares adjustments?

Once you have answered all of the above questions, please email your answers to me. Thank you.