Every user of statistics should understand the distinction between statistical significance and practical importance. A sufficiently large sample will declare very small effects statistically significant. Consider the study of elite female Canadian athletes that investigated whether elite athletes are deficient in their nutritional intake. A total of n athletes from eight Canadian sports centers participated in the study. Female athletes were consuming an average of 2403.7 kcal/day with a standard deviation of 880 kcal/day. Suppose a nutritionist is brought in to implement a new health program for these athletes. This program should increase mean caloric intake but not change the standard deviation. Given the standard deviation and how caloric deficient these athletes are, a change in the mean of 50 kcal/day to 2453.7 is of little importance. However, with a large enough sample, this change can be significant. To see this, calculate theP-value for the test of

H0:μ=2403.7
Ha:μ>2403.7

in the following situation:

A sample of 100 athletes; their average caloric intake is x= 2453.7.

(Fill in the blanks below and roundzto to 2 decimal places and round P to 4 decimal places.)

For n=100, z= P=P(Z >___) =

Prompt: read the following case study and discuss the questions listed at the end of this page. brittany is a 15-year-old freshman in high school. she is the oldest child in a single parent family. she enjoys sports and participates in volleyball, basketball, track, and softball at school. her usual day consists of breakfast at home, which is usually a pop-tart on the way out of the house. lunch is a fast food meal with friends that often consists of a double cheeseburger, fries, and large regular soda pop after which she often feels stuffed and bloated, but feels she needs the calories for her busy sports schedule. she then doesn’t eat again until later in the evening even if she is hungry after school. supper is either a hot dog or pop at ball games or left-over food in the refrigerator after she gets home from practice. she doesn’t care much for fruits and vegetables other than bananas, corn and lettuce salad, as her mom seldom prepares them for the family or keeps fresh fruit on hand. she is 5’6” and weighs 115 pounds and would like to weigh closer to 100–105 pounds. a weight-for-height table puts her weight range at 125 pounds to 135 pounds. she is worried about gaining weight. a cute guy in her math class that she would like to date was overheard talking to his buddies and making fun of large girls in the class. she feels like she is always stressed for time with games and practices, homework to do in the evenings, and household duties she does for her mom who works to support the family. she feels like she has no leisure time for herself. when feeling extra stressed she will eat an entire large bag of potato chips or three to four cups of ice cream and then feel guilty afterward. questions: 1. name some of the components of brittany’s lifestyle and eating patterns that are contrary to the wellness approach to body size and weight management principles covered in this section. 2. what are some improvements she could make based on these principles? name as many as you can. what are some practical ways you can make improvements or healthy things you are already doing?