Question

a chef knows that ground beef used for hamburger is safe to eat once it reaches 160 degrees fahrenheit. for optimized taste and safety, he will not allow a hamburger cooked to a temperature under 160 degrees or over 170 degrees to be served. which graph represents the conditions under which the chef will not allow the hamburger to be served?

Explanation:

Step1: Identify the acceptable range

The acceptable temperature range for serving is $160\leq t\leq170$, where $t$ is the temperature in degrees Fahrenheit.

Step2: Determine the non - acceptable range

The non - acceptable range is $t < 160$ or $t>170$. On a number line, this is represented by an open circle at $t = 160$ (since $t$ is strictly less than 160) and an open circle at $t = 170$ (since $t$ is strictly greater than 170), with arrows pointing to the left of 160 and to the right of 170.

Answer:

The first graph (the one with open circles at 160 and 170 and arrows pointing left from 160 and right from 170)