Off The Formula Sheet
Formula for calculating a residual
A value that ranges between -1 and 1 that tells you the strength and direction of a 2-variable quantitative relationship
(Contrary to popular belief, brown variants of this animal don't produce chocolate milk.)
Correlation coefficient
When the p is low, ...
Reject the
H_o
A situation can be described as binomial if it meets all the requirements of BINS. What does each letter in the acronym BINS stand for?
Binary
Independent
fixed Number of Trials
Same probability each Trial
The mean for combined mean of two independent random variables X and Y
mu_(X+Y)=mu_X+mu_Y
A type of experimental design where experimental units are first grouped into homogenous groups before randomly assigning treatments
(a children's tv show featuring a family of dogs set in Australia)
Block design
RHS claims that the true proportion of students in dress code is .9. Mr. Jackson thinks the proportion of students in dress code is significantly less than the claim. Write the null and alternate hypothesis.
H_o:p=.9
H_a:p<.9
If events A and B are independent and:
P(A)=.7
P(B)=.4
find
P(AcapB)=
P(AcapB)=.28
A significant test was performed for an
H_a:mu<9.8
and the p-value was calculated to be .07
If the alternate hypothesis was then switched to:
H_a:mu!=9.8
How does the p value change?
new p value: (.07)2=.14
An experiment in which both the participate and the researcher don't know who is receiving a particular treatment or placebo
(A spikey foul smelling fruit)
Double-Blind
Some boxes of cereal contain a voucher for a free box of cereal. The company claims that this voucher appears in 20% of all cereal boxes. Anita believes that proportion of all cereal boxes that contain the voucher is less than .2. They take a random sample of 200 cereal boxes and 28 of them contain the voucher.
1-sample z test for p
A class of 28 students has 15 students that play basketball, 10 students that play baseball and 6 students that play neither baseball nor basketball. How many students play both basketball and baseball?
3 students play both sports
The relationship between power and the probability of Type II error
1 - power = P(type II error)
The name for experimental units when they are humans
(The button on an alarm clock that you may hit a few times before you wake up)
Subjects
A bottle filling machine is set to dispense 12.1 fluid ounces into juice bottles. To ensure the machine is filling accurately, every hour a worker randomly selects four bottles filled by the machine and measures its contents. During one hour, the mean number of four randomly selected bottles was 12.05 with a standard deviation of .085 ounces. Is there convincing evidence the machine is dispensing a different amount than 12.1 ounces.
1 sample t test for means
The probability of winning a prize on a particular brand of lottery ticket is .18. What is the average number of tickets it would take someone to win their first prize?
approximately 5.56 tickets
The formula for the combined standard deviation of two random variables X and Y
sigma_(X+Y)=sqrt(sigma_X^2+sigma_Y^2
Standard deviation raised to the second power
(Tarzan is often depicted swinging from one of these)
Variance
We use the t-distribution (instead of the normal distribution) for significance tests when we are working with population means (that may or may not pass CLT) and when...
We don't know the population's standard deviation
15.81 centimeters