7,215: 34 = 0,212205882352941
180 - 53 - 96 = 31°. you know the angles are 53 and 96 degrees because the triangles are congruent via SAS congruency.
Using it's concept, it is found that the sample mean package weight for Thursday is of 19 ounces.
<h3>What is the mean of a data-set?</h3>
The mean of a data-set is given by the <u>sum of the observations divided by the number of observations</u>.
For Thursday, the package weights in ounces are given by: {18, 19, 20, 19}.
Hence, the sample mean in ounces is of:
M = (18 + 19 + 20 + 19)/4 = 19.
More can be learned about the mean concept at brainly.com/question/24628525