A sample of size 101 from a normal population has sample standard deviation s = 40. The lower and upper 0.025 points of the \(\chi_{100}^{2}\) distribution are \(\chi_{100,0.975}^2=74.222\) and \(\chi_{100,0.025}^{2}=129.561\). Use these values to construct a 95% confidence interval for \(\sigma\).

Equation Transcription:

Text Transcription:

chi_100 ^2

chi_100, 0.975 ^2 = 74.222

chi_100, 0.025 ^2 = 129.561

sigma

PSYCH STATS POWERPOINT CHAPTER TWO ● frequency: the number of times a score occurs ● distribution: shape of scores ● frequency distribution: organized display of scores ○ descriptive stats ● tables: simplest format ○ lists every score and frequency ● graphs ○ visual depiction ○ many types Frequency Distribution Table ● find the largest value, write it in the table ● find each time it occurs, record frequency ● repeat ● sum of all scores ○ take each individual score from table ○ multiply each score by the frequency ● proportion: f/n ● percentage: (f/n)100 ● the sum of all the total number of frequencies: n ● if your data set has a large range: use a group frequency table ○ group scores in equal sized groups ○ use about 8-10 groups ● frequency distribution graphs ○ independent variable on x-axis ○ dependent variable on y-axis ● multiple types of graphs ○ depends on scale of measurement ■ interval/ratio ● histogram ● polygons ■ nominals/ordinals ● histogram: ○ bar is centered above each score ○ bars are touching ○ checks for problems in data ● polygon ○ dot in each score column indicating frequency ○ dots connected by straight lines ■ first and last dot connected to x-axis ● population graphs - smooth curves ○ used when graphing interval/r