A suitable probability calculator can tell you the probability is about 6.7%.
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The standard deviation of the distribution of sample means is the population standard deviation (6) divided by the square root of the sample size (√144=12). Thus, your threshold is about (19.25-20)/(6/12) = -1.5 standard deviations from the mean.
Answer:
For this case the factor would be:
Road conditions
Because we are testing a new type of tire in order to determine if the time to 60 mph from a full stop in light raing, ligth snow and dry conditions.
Step-by-step explanation:
Previous concepts
By definition a factor usually known as "the independent variable is an explanatory variable manipulated by the experimenter".
Analysis of variance (ANOVA) "is used to analyze the differences among group means in a sample".
The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"
If we assume that we have groups and on each group from
we have
individuals on each group we can define the following formulas of variation:
And we have this property
Solution to the problem
For this case the factor would be:
Road conditions
Because we are testing a new type of tire in order to determine if the time to 60 mph from a full stop in light raing, ligth snow and dry conditions.
Th use 5 experimental units that are selected from the an specific lot. And they want to test is the stopping distance is significantly different.
And for this case we can use a one way ANOVA to test if the means are equal in the 3 groups.