Vocab
This can be found by dividing the sample standard deviation by the square root of the sample size, and then multiplying by t.
Margin of Error
Which two do I need to find Margin of Error: statistic, critical value, standard error, population size.
critical value and standard error
If (99.8, 104.6) is a 90% confidence interval for a sample of fifteen basketball scores, what is your conclusion about the average scores of the population?
We are 90% confident that the interval contains the population mean basketball scores.
What is the critical Z-value for a 95% confidence interval
1.96
If the mean of a sample is 2.3 and the margin of error is 1.5, what is the confidence interval?
(.8,3.8)
If a confidence interval is from 26.32 to 35.85, what is the mean of the sample?
31.085
Should I use a t-distribution or a z-distribution? Suppose that you want to find out the average weight of all players on the football team at a particular College. You are able to select ten players at random and weigh them. The mean weight of the sample of players is 198 lbs, with a standard deviation of 11.50 lbs.
t
Find the Margin of Error for a 95% z-confidence interval with a standard deviation of 24.2 and a sample size of 40.
7.5
The average heights of a random sample of 400 people from a city is 1.75 m. It is known that the heights of the population are random variables that follow a normal distribution with a standard deviation of 0.4 m. Determine the interval of 95% confidence for the average heights of the population.
n = 400 x = 1.75 σ = 0.4 c = 0.95 z* = 1.96 (1.75 ± 1.96 • 0.4/20 ) → (1.7108, 1.7892)
What town does Mrs. Beigel live in?
What is Dunstable
Should I use a t-distribution or Z? The average heights of a random sample of 400 people from a city is 1.75 m. It is known that the heights of the population are random variables that follow a normal distribution with a standard deviation of 0.4 m. Determine the interval of 95% confidence for the average heights of the population.
Z
What is the margin of error for a sample with a critical value of 1.76, a sample size of 64, and a sample standard deviation of 3.5?
0.77
Suppose that you want to find out the average weight of all players on the football team at a particular College. You are able to select ten players at random and weigh them. The mean weight of the sample of players is 198 lbs, with a standard deviation of 11.50 lbs. Construct a 90 percent confidence interval for the population weight, if you presume the players' weights are normally distributed.
(192, 204)
How many school days until April vacation (not including today) ?
What is 28
What type of interval should I use? 68% of pizzas were ordered with pepperoni as a topping in a random sample of 40 orders from a local pizza place. Determine the interval of 95% confidence for the proportion of all pizzas that are ordered with pepperoni as the topping.
z-interval
If the margin of error of a sample is 3.45, the sample size is 16, and the critical value for the confidence level is 1.876, then what is sample standard deviation?
7.356
If a sample of 36, has a mean of 29, and a standard deviation of 4.3, find a 90% confidence interval for the population mean.
(28.055,29.945)
DAILY DOUBLE: When is Pi Day?
March 14 (3.14)