To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at general electric selects every 20th refrigerator that comes off the assembly line starting with the sixth until she obtains a sample of 130 refrigerators. what type of sampling is used? (a) simple random (b) systematic (c) cluster (d)convenience (e) stratified

 (b) Systematic

Step-by-step explanation:

A systematic random sampling is kind of sampling method in which samples are chosen from a larger population based on a random beginning point that has a definite and periodic interval.

Given statement : To estimate the percentage of defects in a recent manufacturing batch, a quality control manager at General Electric selects every 20th refrigerator that comes off the assembly line starting with the sixth until she obtains a sample of 130 refrigerators.

Periodic interval : Every 20th

Beginning point : 6th

Sample size : 130

Hence, this type of sampling is a systematic random sampling.

First locate the turning point (vertex) of the graph. which is at the coordinates x=5 and y=9 or (5; 9).to determine whether it's a maximum or mininum value, you have to discern whether the vertex's y-value is the highest value or lowest value the graph can reach. since the vertex's y-value, 9 is the highest value the graph can reach, it will be a maximum.another basic way to determine whether the vertex's value is max or min is to see if the graph is smiling or sad. if it's smiling, the turning point/vertex would be a minimum, while a sad parabola would have a maximum y-value at the vertex.