3.9 Almost Passing but Not Quite ENOUGH

3.9 Almost passing but not quite ENOUGH:

No PPDAC headings – the problem and the conclusion are implied, the data is not described….

Print from Inzight these:

Linear Trend SSF = 5.07 * X.Bfat + 0.59 Correlation = 0.96

TARSOG: trend, association, relationship, scatter, outliers, groups

TREND – the trend is linear. (this is the only answer)

ASSOCIATION – the association is positive (the other answer is negative)

Positive means it is going “up hill”, as x gets bigger, y gets bigger (increases)

Negative means it is going “down hill”, as x increases, y decreases

RELATIONSHIP - Possible answers… strong, significant, moderate, insignificant

Correlation = 0.96 from page 22 of sigma (learn by heart)

The relationship is very strong, as the points are close to the line and evenly spread either side of the line. The Correlation = 0.96 confirms this is a strong linear relationship.

SCATTER – Up to 25% bodyfat the scatter is evenly spread either side of the trend line. Over 25% body fat the scatter is above the trend line.

OUTLIERS – the athlete with over 35% body fat and approximately 200mm skin folds is separated from the rest of the data, but not by much so is not really an outlier.

GROUPS – there does seem to be two groups, in the respect of fitting the linear model, those under 25% bodyfat and those over 25% bodyfat. However, when looking at the spread of the rugs and the shape of the data, there are no obvious groups. (to pass just say there are OR are NOT groups).

Summary sentence: You MUST write a sentence about the relationship.

As bodyfat percentage increase, sum of skin folds also increases in AIS Athletes.

Prediction: you MUST make ONE prediction to PASS.

You cannot make predictions if there is no relationship, so CHOOSE two variables that DO have a relationship…

SSF = 5.07 * X.Bfat + 0.59

SSF = 5.07 * 20 + 0.59

I predict that the sum of skin folds of an AIS athlete with a body fat percentage of 20 will be approximately 102mm.

SSF = 5.07 * 15 + 0.59

I predict that the sum of skin folds of an AIS athlete with a body fat percentage of 15 will be approximately 77mm.

SSF = 5.07 * 7 + 0.59

I predict that the sum of skin folds of an AIS athlete with a body fat of 7% will be approximately 36mm.

SSF = 5.07 * 24 + 0.59

I predict that the sum of skin folds of an AIS athlete with a body fat percentage of 24 will be approximately 122mm.

SSF = 5.07 * 17 + 0.59

I predict that the sum of skin folds of an AIS athlete with a body fat of 17% will be approximately 87mm.

SSF = 5.07 * 13 + 0.59

I predict that the …

SSF = 5.07 * 10 + 0.59