At a recent company picnic with over 2000 guests, an outbreak of food poisoning occurred. A doctor suspects that the potato salad may be related to the food poisoning. A random sample of 200 guests asked about their symptoms and whether or not they ate the potato salad. The data is presented in the table below. Ate the potato salad? Yes No Total None 20 25 45 Symptoms Mild 40 20 60 Severe 80 15 95 Total 140 60 200 Do these data provide evidence of an association between potato salad consumption and the severity of symptoms? a. Find the expected frequencies. Fill in the table below. (5 pts.)
Added by Jason V.
Close
Step 1
Step 1: The expected frequency for each cell is calculated as: (row total * column total) / grand total. Show more…
Show all steps
Your feedback will help us improve your experience
Rachel Gore and 98 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
In a case-control study of salmonellosis, the investigators considered its association with potato salad consumption. The 2 x 2 table below summarizes the observed relationship: The odds ratio associated with potato salad eating = ad/bc = 36*36 / 3*12 = 36. All controls were sampled at the end of the study. Is this odds ratio a good approximation of the risk ratio? No, because salmonellosis is neither rare in this population (39 out of 87 were sick) nor did we use incidence density sampling. No, because the odds ratio associated with potato salad eating is too large. Yes, because both exposure and outcome are common in the study population. Yes, because salmonellosis was rare in the non-exposed group.
Rachel G.
An outbreak of gastritis occurred on a cruise ship. The data in the following Table were obtained, shortly after the outbreak, from a questionnaire completed by everyone on board the ship. Food People Who Ate Food People Who Did Not Eat Sick Well Sick Well Herring 200 800 100 900 Chicken 650 350 100 900 Spinach Souffle 200 800 500 500 Oysters 300 700 400 600 Chocolate Mousse 600 400 450 550 1. Calculate the attack rates for each food and show your work (hint, you will need to add some data columns to this table!) 2. What is the relative risk of developing gastritis for herring consumption? Show calculation. 0.5 2.0 2.3 8.0
Sri K.
26. The nutrition label on a bag of potato chips says that a one ounce (28 gram) serving of potato chips has 126 calories and contains ten grams of fat, with three grams of saturated fat. A random sample of 32 bags yielded a sample mean of 130 calories with a standard deviation of 16 calories. Is there evidence that the nutrition label does not provide an accurate measure of calories in the bags of potato chips? We have verified that the independence, sample size, and skew conditions are satisfied. Set this up as a hypothesis test using α=0.01, and show your work for full credit.
Adi S.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD