Statistics Unit

Identify the meaning of "Robust Procedures" in statistics.

• probability calculations are accurate

• the true mean is, in fact, captured by the confidence interval

• procedures have followed which calculate the confidence interval correctly

• probability calculations remain fairly accurate when a condition for the use of the procedure has been violated

• probability calculations are exactly accurate when all conditions for the use of the procedure have been followed

Identify all graphs which help determine the shape of the distribution.

• boxplot

• stemplot

• normal probability plot

• histogram

• scatterplot

Identify the type of confidence interval described.

σ is known

• 1 proportion z interval

• 1 proportion t interval

• z interval

• t interval

Identify the type of confidence interval described.

σ is unknown

• 1 proportion z interval

• 1 proportion t interval

• z interval

• t interval

Identify the type of confidence interval described.

A survey indicates 14 of 71 respondents brush their teeth multiple times per day

• 1 proportion z interval

• 1 proportion t interval

• z interval

• t interval

How is normality established for a proportion problem?

• n ≥ 30, Central Limit Theorem

• np > 10, n(1 - p) > 10

• the distribution shows no outliers, n < 10

• N ≥ 10n

• subjects have been selected using some random process

How is indepedence established for a proportion problem?

• n ≥ 30, Central Limit Theorem

• np > 10, n(1 - p) > 10

• the distribution shows no outliers, n < 10

• N ≥ 10n

• subjects have been selected using some random process

How can normality be established for a means problem?

• n ≥ 30, Central Limit Theorem

• np > 10, n(1 - p) > 10

• the distribution shows no outliers, n < 10

• N ≥ 10n

• subjects have been selected using some random process

Identify how degrees of freedom are calculated.

• df = n

• df = n-1

• df = s/√n

• df = √(p(1-p)/n)

Identify the type of confidence interval described.

degrees of freedom are required to determine the critical value.

• 1 proportion z interval

• 1 proportion t interval

• z interval

• t interval