Standard Normal Distribution
The total area under the standard normal curve equals this number.
1
A population has mean 100 and standard deviation 20. A sample of 64 is taken. What is the standard error?
2.5
This theorem explains why sample means form a normal distribution as sample size increases.
Central Limit theorem
This type of distribution is symmetric and bell-shaped
What is a normal distribution
Who are the two actors sharing the leading role in big fish
Blake and Andrew
According to federal highway administrations 2006 highway statistics, the distribution of ages for licensed drivers has a mean of 47.5 years and a standard deviation of 16.6 years. Assuming the distribution of ages is normally distributed, what percentage of drivers are between the ages 48 and 68?
37.9 (38) percent
The mean weight of apples is 150g with a standard deviation of 30g. If 36 apples are sampled, what is the probability the sample mean exceeds 160g?
0.0228
The CLT applies even if the population distribution is not normal, as long as this condition is met.
n=30, or is large enough
This statistic tells how many standard deviations a value is from the mean
Z score
What is the motto of millbrook in latin and engish
Non sibi sed cunctis: not for oneself but for all
the middle 80%, or 0.8000, of a normal distribution is bounded by z=-1.28 and 1.28.
4900 is the difference between the x value and the value of the mean, (the numerator of formula: x - M = 4900.). Using formula, find the value of the standard deviation:
3828
Life Expectancies In a study of the life expectancy of 500 people in a certain geographic region, the mean age at death was 72 years, and the standard deviation was 5.3 years. If a sample of 50 people from this region is selected, find the probability that the mean life expectancy will be less than 70 years.
0.0025
The mean of the sampling distribution is equal to this
population mean
This rule describes the 68%, 95%, and 99.7% pattern in normal distributions.
Empirical Rule
you cant hum while holding this part of your body
nose
Find the 33rd percentile for IQ scores (M = 100. standard deviation = 16
92.96
Home Values A study of 800 homenwners in a certain area showed that the average value of the homes was $82,000, and the standard deviation was $5000. If 50 homes are for sale, find the probability that the mean of the values of these homes is greater than $83,500
0.0143
teacher checks
This measures the spread of a distribution and tells how far values typically are from the mean.
standard deviation
this condition magically appears after college applications are submitted
senioritis
In a large class, suppose your instructor tells you that you need to obtain a grade in the top 10% of your class to get an A on a particular exam. From past experience she is able to estimate that the mean and standard deviation on this exam will be 72 and 13. What will be the minimum grade needed to obtain an A
89
On the Trends in International Mathematics and Science Study test in a recent year, the United States scored an average of 508. Suppose that we take a random sample of n United States scores and that the population standard deviation is 72. If the probability that the mean of the sample exceeds 520 is 0.0985, what was the sample size?
60
This term describes the percentage of data below a given value.
Percentile
bananas are technically this type of food, but strawberries are not
a berry