Terms
If a continuous random variable has a distribution with a graph that is symmetric and bell-shaped, it is said to be a what?
Normal distribution
The area under the curve or the probability of something is 0.1977. What is the corresponding z score?
-0.85
What type of estimators do NOT target the value of the corresponding population parameter?
Biased estimators
For there to be a correspondence between area and probability, the area under a density curve must be equal to what value?
1
What is the formula / equation for a z score in relation to an individual? This is the regular or one we used for the majority of the unit.
z = (x - u) / o
What is a graph of points (x , y) where each x value is from the original set of sample data, and each y value is the corresponding z score that is a quantile value expected from the standard normal distribution?
Normal quantile plot
What is the probability that a randomly selected person has a bone density test result less than 1.96?
0.9750
Mean, variance, and proportions are examples of what kind of estimators?
Unbiased
Our textbook requires us to round z scores to how many decimal places?
2
Ex: 1.23456 would be 1.23
Your z score is negative, what page are you using to find the corresponding area under the curve
724
This is the distribution of all values of the statistic when all possible samples of the same size n are taken from the same population. (Hint: this is very similar to 3 other definitions, but most of you only wrote this one down)
Sampling distribution of a statistic
What is the probability that a randomly selected person has a bone density test result greater than 0.82?
0.2061
What are three examples or statistics of biased estimators?
Median, range, and standard deviation
According to the Central Limit Theorem, if the population is not normally distributed, what values of sample sizes "n" can be approximated by a normal distribution?
n > 30
What is the z score conversion for a group's mean?
(x - u) / o / sqrt(n)
A statistic that targets the value of the population parameter.
Unbiased estimator
What is the probability that a randomly selected person has a bone density test result between 0.25 and 1.25?
0.2957
The distribution of sample means, variances, and proportions tend to approximate what kind of distribution?
Normal / Bell-shaped
What do the values for the mean and standard deviation have to be for a standard normal distribution respectively?
Mean = 0
Standard Deviation = 1
Does a uniform histogram translate to a normal or not normal quantile plot?
Not normal (Follows a systematic pattern)
What is the term used to represent a whole number x as an interval from x - 0.5 and x + 0.5?
Continuity correction
Men's heights are normally distributed and have a mean of 69.5 in. with a standard deviation of 2.4 in. Find the height of men that separates the top 95% from the bottom 5%. In other words, find the 95th percentile of men's heights in inches.
73.4 inches
(Page 263)
FINAL JEOPARDY
Catching some ZZZ score's
Are the two conditions met for a Normal Distribution as an Approximation to the Binomial Distribution if n = 40 and p = 0.9?
No,
np ≥ 5 passes (40 * 0.9) = 36
nq ≥ 5 does not pass (40 * 0.1) = 4
If the probability asks for an x value of at most 2024, at what number and direction does the shading start if having to use the continuity correction?
To the left of 2024.5