Worksheet2

docx

School

Unity College *

*We aren’t endorsed by this school

Course

201

Subject

Mathematics

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by PrivateComputerSparrow38

MATH 201 Statistics for Environmental Professionals ● Worksheet 2 Name Section 1. Suppose that you work to control the spread of infectious disease. One of your tasks is understanding the pathway and sex differences in Zika virus infections. The following table represents the confirmed and probable non-congenital cases of Zika virus disease in 50 U.S. states and the DC in 2016 by mode of infection and sex. Refer to the textbook 3.2 – 3.4. Female (F) Male (M) Total Travel-associated (T) 3,163 1,734 4,897 Local mosquito-borne (L) 103 121 224 Total 3,266 1,855 5,121 Note: Data collection has often categorized findings by binary sex. Question 1. Find the probability that a randomly selected case from all cases represented in the table is travel-associated. Note this is P(T). Show your work. (10 pts.) P(T) = 4897/5121 P(T) = 0.956 Question 2. Find the probability that a randomly selected person represented in this table is female AND travel associated. Note this is P(F AND T). Show your work. (10 pts.) P(F AND T) = 3163/5121 P(F AND T) = 0.617 Question 3. Find the probability that a randomly selected case from all cases represented in the table is female OR travel associated. Note this is P(F OR T). Show your work. (10 pts.) P(F OR T) = P(F) + P(T) – P(F AND T) P(F OR T) = 3266/5121+4897/5121-3163/5121 P(F OR T) = 0.956+0.956-0.617 P(F OR T) = 1.295 Question 4. Find the conditional probability that a randomly selected case from all cases represented in the table is travel-associated given the person is female. Note this is P(T | F). Show your work. (10 pts.) P(T/F) = 3163/3266 = 0.968 Question 5. Based on the probabilities you have calculated for Questions 1 to 4. What is your conclusion concerning the pathway and sex differences in Zika virus infection? (10 pts.) There were more female cases than male cases, with a total of 3266 female cases compared to 1855 male cases. Females were more likely to contract the Zika virus through travel than men.

Section 2. Suppose that you work for a government sector for water resources management. Your section is responsible for estimating the required water for household use. Assume that the volume of daily water use per household in North America follows a normal distribution. The mean volume of daily water use is 138 gallons per household and the standard deviation is 46 gallons. Question 1. Sketch (by hand or digitally) the distribution of daily water use (in gallons) per household in North America. Clearly label x and y-axis. (10 pts.) Question 2. Find the probability that a randomly selected household in North America uses less than 69 gallons of water daily. Calculate the z-value using the formula and find the probability using the z-table or other technology (e.g. calculator). Show your work. (10 pts.) Z = (69-138)/46 = -1.5 0.0668 Question 3. Find the probability that a randomly selected household in North America uses greater than 161 gallons of water per day. Calculate the z-value using the formula and find the probability using the z- table or other technology (e.g. calculator). Show your work. (10 pts.) Z + (161-138)/46 = 0.5 0.6915 Question 4. Find the probability that a randomly selected household in North America uses between 69 and 161 gallons of water daily. Show your work. (10 pts.) 1-(0.0668+0.6915 = 1- 0.7583 = 0.2417

Question 5. Find the 90 th percentile of the value of daily water use per household in gallons. Use the formula of z-score and either z-table or other technology (e.g. calculator). Show your work. (10 pts.) X = 138+1.28*46x = 138+58.88x = 196.88

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Worksheet2

Related Documents