Confidence Interval
The formula for a t confidence interval.
What is x̄±t*(s/sqrt(n))
The degrees of freedom of a study that finds a sample of 1200 kids to have a mean test score of 85% and a sample standard deviation of s=5%.
What is 1199 kids?
The formula for a t-value.
What is t=(x̄-µ)/(s/sqrt(n))
The formula for the standard error of a t confidence interva
What is s/sqrt(n)?
The one-sided P-value for a study of how fast turtles walk if the study records the walking speed of 12 turtles and finds a sample mean of 3 mph and a sample standard deviation of 1 mph with a confidence level of 50%.
What is .25?
The t* of a study of 15 cheetahs if it is determined that the cheetahs have a sample mean of 75 mph and a sample standard deviation of 5 mph with a confidence level of 99.5%
What is 3.326?
The sample size that gives a margin of error of at least 2 inches for a study of the length of rhinoceros horns that has a sample mean of x̄=8in and a sample standard deviation of s=1in with a t* value of 6.12.
What is 10 Rhinos?
A study is done that determines the length of geckos to be normally distributed with µ=7in. Amanda believes the mean length of geckos is less than 7in and conducts her own study where she randomly measures 10 geckos and finds their mean length to be 6 inches and sample standard deviation to be s=1in. She conducts her study using a confidence level of 95%. What is the null hypothesis, alternative hypothesis, P-value, and statistical significance of the P-value at a significance level of α=.05.
A: Ho: µ=7in, Ha: µ<7in, P=.0057, Statistically significant and reject null hypothesis
The t* of a study of the height of pandas if the study sampled 29 pandas and found a sample mean of 3ft and a sample standard deviation of 6in with a two sided P-value of .30 and a 70% confidence level.
What is 1.056?
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 time it takes to download a video game has a population mean of µ=2 hrs. 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 and the sample standard deviation to be s=50 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 is between .01 and .005, Statistically significant and reject null hypothesis
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 approximate sample size of a study of the time it takes for people to get ready in the morning if the time it takes people to get ready in the morning has a confidence interval of 15 minutes to 50 minutes with a sample standard deviation of s=1500 seconds and a t* of 3.62
What is 27 people?
The weight of koalas is normally distributed with µ=20 lbs. 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 and gets a sample standard deviation of 5lbs. 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=20lbs, Ha: µ≠20lbs, P is between .02 and .04, Not statistically significant and can not reject null hypothesis
The t*'s that the t-value of a study of the time it takes to cook minute rice falls between if the population mean of minute rice is 1 minute and the time it takes to cook 23 randomly selected minute rice packages have a sample mean of 61 seconds and a sample standard deviation of 2 second.
What is 2.183 and 2.508?