Questions: A researcher for the EPA measured the amount of arsenic in the water near a sewage treatment plant. Over 12 days, he took n=40 measurements (in ppb). His sample data is summarized in the frequency distribution polygon shown below. How many measurements taken in this time frame were within [65,70) ppb?

A researcher for the EPA measured the amount of arsenic in the water near a sewage treatment plant. Over 12 days, he took n=40 measurements (in ppb). His sample data is summarized in the frequency distribution polygon shown below. How many measurements taken in this time frame were within [65,70) ppb?
Transcript text: A researcher for the EPA measured the amount of arsenic in the water near a sewage treatment plant. Over 12 days, he took $n=40$ measurements (in ppb ). His sample data is summarized in the frequency distribution polygon shown below. How many measurements taken in this time frame were within $[65,70)$ ppb?
failed

Solution

failed
failed

Solution Steps

Step 1: Identify the relevant range

The problem asks for the number of measurements within the range [65, 70] ppb.

Step 2: Locate the data points on the frequency polygon

Examine the frequency polygon to find the data points corresponding to the range [65, 70] ppb.

Step 3: Read the frequency values

From the frequency polygon:

  • At 65 ppb, the frequency is 8.
  • At 70 ppb, the frequency is 10.

Final Answer

The number of measurements taken in the time frame within [65, 70] ppb is 18.

Was this solution helpful?
failed
Unhelpful
failed
Helpful

Questions asked by other users

failedAnswered
The relationship between Celsius temperature, C, and Fahrenheit temperature, F, can be described by a linear equation in the form F=mC+b. The graph of this equation contains the point (100,212) : Water boils at 100°C or 212°F, The line also contains the point (0,32) : Water freezes at 0°C or 32°F. Write the linear equation expressing Fahrenheit temperature in terms of Celsius temperature. F ≈
failedAnswered
A timber company in northern Georgia is harvesting pine trees to sell by the cord. A typical acre produces 13.85 cords of wood, and the company sells each cord for 19.20. How much money can the timber company expect to make from each acre of pine trees?
failedAnswered
What is the molarity of a 0.30 L solution with 43 g H2SO4? Select the correct answer below: 0.8 M 1.1 M 1.5 M 1.7 M
failedAnswered
An adult with a healthy sleep cycle is most likely to enter REM sleep in which of the following ways? (A) immediately after falling asleep (B) after the dream stage is completed (C) after cycling through the NREM sleep stages (D) soon after falling asleep and then remain there for the majority of the night
failedAnswered
Find the derivative of f(x) = 2 / (3x). f'(x) = -2 / (3x^2)