3.1: measures of center. find the weighted average.\nin your history class, your final grade is based on…

3.1: measures of center. find the weighted average.\nin your history class, your final grade is based on four categories. the categories are tests, labs, assignments, and a final exam. suppose you earned the following grades in each of the categories; 56% on tests, 78% on labs, 46% on assignments, and 66% on the final exam. if tests are worth 22%, labs are worth 5%, assignments are worth 16%, and the final exam is worth 57%, determine your final grade in the course. record the grade below as a percentage accurate to two decimal places.\nfinal grade: \nenter an integer or decimal number more...\nquestion help: message instructor post to forum
Answer
Explanation:
Step1: Recall weighted - average formula
The formula for the weighted average $\bar{x}=\sum_{i = 1}^{n}w_ix_i$, where $w_i$ is the weight and $x_i$ is the value.
Step2: Identify values and weights
Let $x_1 = 56$, $w_1=0.22$ (22% as a decimal); $x_2 = 78$, $w_2 = 0.05$ (5% as a decimal); $x_3=46$, $w_3 = 0.16$ (16% as a decimal); $x_4 = 66$, $w_4=0.57$ (57% as a decimal).
Step3: Calculate the weighted - average
$\bar{x}=w_1x_1 + w_2x_2+w_3x_3 + w_4x_4$ $=0.22\times56+0.05\times78 + 0.16\times46+0.57\times66$ $=0.22\times56 = 12.32$ $0.05\times78=3.9$ $0.16\times46 = 7.36$ $0.57\times66 = 37.62$ $\bar{x}=12.32 + 3.9+7.36+37.62$ $=61.2$
Answer:
$61.20$