Definitions
Always remains on or above the horizontal axis and has a total area of 1 underneath it.
What is the Density Curve?
3 features of normal distributions
What is symmetric, single peaked, bell-shaped, described by its mean and standard deviation.
The equation for standardized value
What is Z = (x - µ) /ơ
Graph where Mean=Median and it is bell shaped with a single peak.
What is a Normal Curve?
The data set has been transformed to have a Mean= 0 and the Standard Deviation=1.
What are standardized scores?
What is a standard normal curve?
SAT scores are N(1024,229). A score of 1482.
What is a score 1 standard deviation above the mean?
N(64.5, 2.5) If x = 60. Find the z-score.
What is -1.8?
A graph for Z>2.85 should be shaded in this direction.
What is shade the area to the right?
Percent of the distribution that is at or to the left of the observation
What is Percentile?
SAT scores are N(1024,229). A score of 795.
What is a score 1 standard deviation below the mean.
SAT N(500, 100) and ACT N(18, 6). This student scored a 720 on the SAT and an 18 on the ACT. This score is more appealing to the universities.
What is the SAT score?
True or False A density curve can be used to help define the shape of a bar graph.
What is False?
Where the slope of the bell shaped curve changes, usually 1, 2 & 3 standard deviation away from the mean.
What is the point of inflection?
N (69, 2.5) The X value at 0.15%
What is 61.5?
SAT N(500, 100) Percent score between 500 and 670 on a test.
What is 45.54%?
In a normal distribution, what percent of the data falls within 1.3 standard deviation of the mean?
What is 0.8064?
If the Normal probability plot is this, then we can say the distribution is approxximately Normal.
What is linear?
Heights of adult women in inches are approx. normal N(65, 2). If Ronda is at the 99th percentile in height for adult women, than her height, in inches, is closest to ___.
What is 71?
The distribution of the weights of loaves of bread has an approx. normal distribution. Using a very large sample, it was found that 10% of the loaves weighed less than 15.34 ounces, and 20% of the loaves weighed more than 16.31 ounces. What are the mean and standard deviation of the distribution of the weights of the loaves of bread?
What is Mean= 15.93 Standard Deviation= 0.46?
In a normal distribution, what percent of values are either lower than 1 SD below the mean or higher than two SD above the mean?
What is 0.1814 or about 18.14%?