Random 1
A major indicator between using a z test and t test
What is the population standard deviation and sample standard deviation?
The type of error if an innocent person is found guilty when the null hypothesis is that someone is innocent and the alternative hypothesis is that someone is guilty
What is a type 1 error?
The two other equations that can be found in the confidence interval equation
What is the margin of error and the standard error?
The formula for degrees of freedom
What is n-1?
The percent of marbles in a bag that are blue if 20% of the marbles are red, 5% are white, 30% are green, and 15% are black
What is 30%?
The function on a graphing calculator for finding z* if only given a confidence level and the things you plug into that function
What is invNorm, area is CL or (((1-CL)/2)+CL), µ=0, σ =1?
The excel formula you use if you are given a percentage and want to cnvert it into a z score
What is norm.inv?
The method for finding a t confidence interval using a graphing calculator when you are given a sample of data
What is plug sample data into list, use t interval function?
The sample size that gives a margin of error of at least 1.2 for a study of the weights of narwhals that has a sample mean of x̄=1200 and a standard deviation of σ=30lbs with a confidence level of 99%
What is 4,147 narwhals?
The t-value of a study of the weight of snakes if the study sampled 9 snakes and found a sample mean of 4 pounds and a sample standard deviation of 1 pound if the population mean of snakes is 5 pounds.
What is -3?
The equation for a 2 sample t interval
What is (x1-x2)+-t*sqrt((s1^2/n1)+(s2^2/n2))?
The meaning of µ being greater than 0 when µ denotes µ1-µ2
What is µ1>µ2?
The upper limit of a 90% confidence interval of the trunk length of elephants if a study of 100 elephants has a sample mean of x̄=7ft with a standard deviation of σ=1ft.
What is 7.1645ft?
The time it takes to download a video game is normally distributed with µ=2 hrs and σ=1hr. Dave believes it takes longer than 2 hrs to download a video game and so he randomly downloads 20 video games and finds the average time it takes to download a video game to be 2 hours and 30 minutes. What is the null hypothesis, alternative hypothesis, P-value, and statistical significance of the P-value at a significance level of α=.01.
Ho: µ=2hrs, Ha: µ<2hrs, P=.0125, Not statistically significant and can not reject null hypothesis
The probability of rolling two 6 sided die and getting sums of 2, 3, 7, and 10.
What is .33?
The upper limit of a 96% confidence interval of a study of the weights of 20 sheep with a sample mean of x̄=200lbs and a sample standard deviation of s=100lbs
What is 249.3 lbs?
The probability that a randomly selected person listens to 11 hours to 16 hours of music or 2 hours to 4 hours of music if the amount of time people spend listening to music every week is normally distributed with µ=10hrs and σ=3hrs.
What is .3869?
The significance of a study of the effects of sleep on college student test scores if scientists believe that having a good nights sleep causes students to score higher if the scientists took a a sample of 10 college students who did not get a lot of sleep before an exam and found their test scores had a x1=76 and s1=6 and a sample of 10 college students who did get a lot of sleep before an exam and found their test scores had a x2=84 and s2=8. Use a significance level of .05.
Statistically Significant, Reject Null Hypothesis, P=.0108976
The weight of koalas is normally distributed with µ=20 lbs and σ=6lbs. Steve believes the average weight of koalas does not equal 20lbs. He measures the weights of 30 randomly selected koalas and finds their mean weight to equal 18lbs. What is the null hypothesis, alternative hypothesis, P-value, and statistical significance of the P-value at a significance level of α=.05.
Ho: µ=20lbs, Ha: µ≠20lbs, P=.0672, Not statistically significant and can not reject null hypothesis
The margin of error for a two sample t confidence interval
t*sqrt((s1^2/n1)+(s2^2/n2))