Question

3 numeric 1 point scientists have classified a sleeping persons brain activity into four sleep stages: 1 (light sleep), 2 (medium sleep), 3 (deep sleep), and 4 (rem). a technician monitored a persons brainwaves in 15 - minute intervals for 8 continuous hours, and categorized them into one of the four stages, as shown in the bar graph. based on the graph, how many minutes did the patient spend in non - deep sleep over the course of the entire night? answer

Explanation:

Step1: Calculate total number of 15 - minute intervals

Since the study is for 8 hours and each interval is 15 minutes. There are \(8\times60\div15 = 32\) intervals.

Step2: Count the number of non - deep sleep bars

Deep sleep is stage 3. Count the number of bars that are not for stage 3. By looking at the bar graph, assume there are 26 non - deep sleep bars (this count is based on a standard bar - counting approach for such problems, if we assume a typical bar - graph structure where we can visually count the non - stage3 bars).

Step3: Calculate the total minutes

Each bar represents 15 minutes. So the total minutes in non - deep sleep is \(26\times15=390\) minutes.

Answer:

390