Warm UpI can determine causation versus

association1. The weight kettle balls produced by a machine as a mean of 5 pounds and standard deviation of .15 pounds.a. What percent of kettle balls weigh

between 4.7 and 5.15 pounds?b. 99.7% of the kettle balls produced weigh

in what interval?2. Determine the sample size with a margin of error 3.5%

1. The weight kettle balls produced by a machine as a mean of 5 pounds and standard deviation of .15 pounds.a. What percent of kettle balls weigh

between 4.7 and 5.15 pounds?

b. 99.7% of the kettle balls produced weigh in what interval?

2. Determine the sample size with a margin of error 3.5%

Homework Questions

Association versus CausationA dietitian studying the nutritional value of eating spinach surveyed a large sample of individuals and recorded their spinach consumption and their physical strength. The dietitian found that the sample of spinach eaters was significantly stronger than the sample of non-spinach eaters.

Can the dietitian conclude that eating spinach causes a person to be stronger?

Association versus CausationWhat would cause a person to eat spinach and have physical strength?

A Lurking Variable is not included in a study but has an affect on variables in the study

Eat Spinach

PhysicalStrength

Association

Cause Cause

Association versus CausationA researcher determines that student athletes who wear helmets are more likely to suffer at least one concussion in high school.

Can the researcher determine that wearing helmets causes student athletes to suffer

concussions?

Association versus CausationWhat would cause a student athlete to wear a helmet and also be more likely to suffer from a concussion?

Wears Helmet

SuffersConcussion

Association

Cause Cause

Association versus CausationConsider a medical study on hearing loss. What lurking variables might there be?

Eat Prunes

HearingLoss

Association

Cause

Cause

FalseTeeth

Association

Grey Hair

Association

Cause

Cause Cause

Association versus CausationFor each headline, determine at least one lurking variable that may be the cause of the association stated.1. “Calcium in diet may cut risk for some cancers,

study finds”2. “Study: Family time declines as Web use booms”3. “Chocolate is linked to depression”4. “Study: Kids who were spanked have lower IQs”5. “Study: Couples who cohabit more likely to

divorce”

BREAK

Showing Cause and EffectAn experiment is based on a statistical question that requires some type of change or treatment be imposed on groups of subjects or objects so that direct comparisons can be made.

In an experiment, the lurking variables can be divided between the treatment groups using randomization. This allows for controlling the lurking variable.

Showing Cause and Effect“Does a new type of motor oil improve gas

mileage?”Imagine you surveyed car owners, some of whom use a new type of motor oil and other who do not and compare the mean gas mileage.What are some problems with this method?Design an experiment that would control for

these lurking variables

Showing Cause and Effect“Does a classroom SAT prep course improve

scores more than an online course?”What are some lurking variables to take into consideration?Design an experiment that would control for

these lurking variables

Showing Cause and EffectDesign experiments to answer the following questions:1. Does listening to classical music during a

math test improve test scores?2. Do seat belts save lives in a car crash?3. Does vitamin C help prevent colds?

QuizYou may use your notes

When done, turn into the INBOX

Graphing Polynomials Review WS