Vocab
This is the number of free choices allowed by my parameter, and can be found by subtracting 1 from the sample size
Degrees of freedom
Which are needed to find Margin of Error: sample mean, critical value, sample size, population size
critical value, sample size
What are our three most commonly used z critical values used for confidence intervals for proportions? (90%, 95%, and 99%)
1.64, 1.96, and 2.58
If my sample size is 12, how many degrees of freedom are there?
11
Which Disney film features the famous dialogue, “Mirror, mirror”?
Snow White and the Seven Dwarfs
This is added and subtracted from the sample mean in order to construct a confidence interval
Margin of Error
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)
In a survey of 1035 US adults, 745 say they want to play pickleball regularly. What is p-hat?
.72
If a confidence interval is from 26.32 to 35.85, what is the mean of the sample?
31.085
Stitch is also known as Experiment _____
626
This is built around a sample statistic (proportion or mean) in an effort to better approximate a population parameter.
Confidence Interval
Find the Margin of Error for a 95% t-confidence interval with a sample standard deviation of 24.2 and a sample size of 30.
9.0358
A 99% confidence interval for proportions comes out to (.445, .601). What is the margin of error?
.078
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)
A sealed VHS of this 2007 Disney movie sold on ebay for $8,750!
Cars
This is another name for the z/t scores we use when approximating a confidence interval
Critical value
What is the margin of error for a sample with a critical value of 1.76, a sample size of 64, and a sample proportion of .33?
.103
In a survey of 2022 US adults, 1167 think antibiotics are effective against viral infections. Find a 95% confidence interval for the population proportion.
(.556, .599)
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)
Who of the following is not a Disney princess?
Moana
Pocahontas
Mulan
Tinker Bell (Peter Pan)
Belle (Beauty and the Beast)
Vanellope (Wreck-It Ralph)
Tinker Bell and Venellope
How do we appropriately say each of these variables...
p-hat
x-bar
s "sub" x
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
Gallup is a company that carries out daily opinion polls on a variety of topics. In a recent daily poll of 1000 randomly selected US adults, 334 said they were engaged at work.
Based on this sample, construct a 90% confidence interval for the proportion of all US adults who would say they are engaged at work.
(.309, .359)
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)
Who was the first character created by Walt disney?
Oswald the Lucky Rabbit