researchers measured the heart rates of several randomly selected astronauts exercising on stationary…

researchers measured the heart rates of several randomly selected astronauts exercising on stationary bicycles during long - term space missions. the researchers found the mean heart rate of the astronauts was 155 beats per minute with a margin of error of 12 beats per minute at a 90% confidence level. which of the following is the most plausible value for the mean heart rate of all astronauts exercising on stationary bicycles during long - term space missions?\nchoose 1 answer:\na 130 beats per minute\nb 140 beats per minute\nc 160 beats per minute\nd 175 beats per minute

researchers measured the heart rates of several randomly selected astronauts exercising on stationary bicycles during long - term space missions. the researchers found the mean heart rate of the astronauts was 155 beats per minute with a margin of error of 12 beats per minute at a 90% confidence level. which of the following is the most plausible value for the mean heart rate of all astronauts exercising on stationary bicycles during long - term space missions?\nchoose 1 answer:\na 130 beats per minute\nb 140 beats per minute\nc 160 beats per minute\nd 175 beats per minute

Answer

Explanation:

Step1: Calculate the confidence interval

The formula for a confidence interval is (\text{Sample Mean}\pm\text{Margin of Error}). Given the sample mean (\bar{x} = 155) and margin of error (E=12). The lower bound of the confidence interval is (155 - 12=143). The upper bound of the confidence interval is (155 + 12 = 167).

Step2: Check each option

  • Option A: (130<143), so it is not in the confidence interval.
  • Option B: (143<140<167) is false. Wait, no, (140<143), so it is not in the confidence interval. Wait, no, correction: The confidence interval is ([155 - 12,155 + 12]=[143,167]). Option B: (140<143), not in the interval. Option C: (143<160<167), so (160) is in the confidence interval. Option D: (175>167), not in the confidence interval.

Answer:

C. 160 beats per minute