stats exam 2 symbols

which symbol represents the level of significance?

α

which symbol represents the best point estimate for the true proportion?

p̂

which symbol represents the best point estimate for the true mean?

x̄

which symbol represents the sample mean?

x̄

which symbol represents the critical value used in confidence intervals for means?

t\*

which symbol represents the sample standard deviation?

s

which symbol represents the sample proportion?

p̂

which symbol represents the margin of error?

E

which symbol represents the population mean?

μ

which symbol represents the standardized value?

z

which symbol represents the population proportion?

p

which symbol represents the critical value used in confidence intervals for proportions?

z\*

we use data from the ___ to make an inference about the ____

sample, population

beyond representative sampling, what assumptions are needed to satisfy the requirements of a one-sample proportion interval?

the number of successes and failures should both be at least 5 and the number of successes should follow a binomial distribution

beyond representative sampling, what assumptions are needed to satisfy the requirements of a one-sample mean interval?

the sample size should be at least 30 or the population have a normal distribution

according to the _______ we can trust the studies with large sample sizes more than we can trust a study with smaller sample sizes

law of large numbers

according to the ______ the sample means of random samples from a population with some mean and standard deviation can be approximated by the normal distribution as the sample size gets large enough

central limit theorem

the half-width of a confidence interval is known as what?

margin of error

confidence intervals are estimates about what?

population parameter