Estimating Parameters
The best estimate for the population mean
What is sample mean?
Of 94 adults selected randomly from one town, 62 have health insurance. A 90% confidence interval for the proportion of all adults in the town who have health insurance with have this as the point estimate.
In a survey of 100 people, 56 said they like pepperoni on their pizza. This is the point estimate for a 95% confidence interval for the population proportion.
What is 0.56?
Which two conditions are identical when checking to see if an interval can be constructed for both qualitative and quantitative data?
What are the random and independent (10%) conditions?
How do you calculate degrees of freedom?
What is n-1?
The best estimate for the population proportion
What is the sample proportion?
Of 94 adults selected randomly from one town, 62 have health insurance. A 90% confidence interval for the proportion of all adults in the town who have health insurance will have this as the critical value.
What is 1.645?
The critical value for this level of confidence is 1.96 when constructing a confidence interval for the population proportion
What is 95%?
The confidence interval does this as the confidence level gets higher
What is the confidence interval gets wider?
What is the t-score for a 95% confidence level and a sample of n=22?
What is 2.08?
The point estimate of students who have jobs when 200 are surveyed and 140 answer yes to having a job
What is p = 0.70?
Of 94 adults selected randomly from one town, 62 have health insurance. A 90% confidence interval for the proportion of all adults in the town who have health insurance will have this as the standard error.
The level of confidence for this critical value is 99% when constructing a confidence interval for the population proportion
What is 2.576?
The conditions for a sample to be sufficiently large to estimate the population mean, given population standard deviation.
Population is assumed to be Normally distributed OR
n >= 30
What value should you use for p hat when calculating for a desired margin of error, if a reasonable estimate for p hat is not available?
What is 0.5?
These are the values needed to find the standard error of the population proportion
What is n and "p hat"?
Of 94 adults selected randomly from one town, 62 have health insurance. A 90% confidence interval for the proportion of all adults in the town who have health insurance is this.
What is (0.579, 0.740)?
This is the interpretation of a confidence interval of (0.154, 0.354) with a 99% level of confidence about adults in a town that smoke.
What is we are 99% confident that the true proportion of all adults in a town that smoke falls between 0.154 and 0.354?
The condition for a sample to be sufficiently large to estimate the population proportion.
nhatp>=10 and nhatq>=10
Why are you NOT able to construct a qualitative interval for the following example:
A random sample of 175 is taken from a small village (population 1,500), and 100 of the villagers report that they own a cow/
What is the 10% condition?
The standard error will reduce by a factor of 2 when we do this to the sample size
What is quadruple the sample size?
Of 94 adults selected randomly from one town, 62 have health insurance. A 90% confidence interval for the proportion of all adults in the town who have health insurance is interpreted as this.
What is we are 90% confident that the interval from 0.579 to 0.740 captures the true proportion of all adults in the town who have health insurance?
In a survey of 25 people, 10 said they don't like to listen to music while studying. This is a 95% confidence interval for the population proportion.
What is (0.208, 0.592)?
The population proportion is believed to be 20%. What sample size is necessary for a 95% confidence interval to confirm this proportion within 3%.
A minimum sample of 683.
Are all conditions met to construct a quantitative interval?
A random sample of 8 is taken from a large population of candy bars. It is known that the weights of these candy bars are normally distributed. The mean weight is 15.2 oz with a standard deviation of 1.1 oz.