Matched pairs (dependent) 2 samples
9.3 t-Test and t-Interval
https://davidwills.us/stat200/TwoSampPairedDepHypo_CI.html
"Visualize 2 dependent samples"
https://davidwills.us/stat200/two_Dep_samples.html
In the Visualizer:
Use the "Cholesterol before and after heart attack" data.
270 236 210 142 280 272 160 220 226 242 186 266 206 318 294 282 234 224 276 282 360 310 280 278 288 288 244 236
218 234 214 116 200 276 146 182 238 288 190 236 244 258 240 294 220 200 220 186 352 202 218 248 278 248 270 242
n=____
X1 mean=______ X2 mean=_______
X1 SD =______ X2 SD =_______
Does it look like cholesterol increased, decreased, or stayed the same:________
(i.e. more red: decrease, more black: increase)
mean of the paired differences d_bar=_______
X1 mean - X2 mean =_______
Paste the data into the "t-Test and t-Interval" webpage.
Do a Two-tailed hypothesis test that the means are different. Ha!=H0
t=______
Critical value .05=______ Reject H0?:_____
Critical value .01=______ Reject H0?:_____
p-value=_______
Reject H0 at α=.05?:_____
Reject H0 at α=.01?:_____
95% CL: E=_____ CI:[_____,______] Contains 0?:____ Reject H0?:___
99% CL: E=_____ CI:[_____,______] Contains 0?:____ Reject H0?:___
************************************************************
In the Visualizer:
Use the "hypnotism" data.
6.6 6.5 9.0 10.3 11.3 8.1 6.3 11.6
6.8 2.4 7.4 8.5 8.1 6.1 3.4 2.0
n=____
X1 mean=______ X2 mean=_______
X1 SD =______ X2 SD =_______
Does it look like the data increased, decreased, or stayed the same:________
(i.e. more red: decrease, more black: increase)
mean of the paired differences d_bar=_______
X1 mean - X2 mean =_______
Paste the data into the "t-Test and t-Interval" webpage.
Do a Two-tailed hypothesis test that the means are different. Ha!=H0
t=______
Critical value α=.05=______ Reject H0?:_____
Critical value α=.01=______ Reject H0?:_____
p-value=_______
Reject H0 at α=.05?:_____
Reject H0 at α=.01?:_____
95% CL: E=_____ CI:[_____,______] Contains 0?:____ Reject H0?:___
99% CL: E=_____ CI:[_____,______] Contains 0?:____ Reject H0?:___
Look at the Visualizer again, it's all red but that one black line of increase
is preventing rejecting H0 at the 99% CL.
************************************************************
In the Visualizer:
Use the "Banks' deposits. 3 years ago and now" data..
11.42 8.41 3.98 7.37 2.28 1.10 1.00 0.9 1.35
16.69 9.44 6.53 5.58 2.92 1.88 1.78 1.5 1.22
n=____
X1 mean=______ X2 mean=_______
X1 SD =______ X2 SD =_______
Does it look like the bank deposits increased, decreased, or stayed the same:________
(i.e. more red: decrease, more black: increase)
mean of the paired differences d_bar=_______
X1 mean - X2 mean =_______
Paste the data into the "t-Test and t-Interval" webpage.
Do a Two-tailed hypothesis test that the means are different. Ha!=H0
t=______
Critical value α=.05=______ Reject H0?:_____
Critical value α=.01=______ Reject H0?:_____
p-value=_______
Reject H0 at α=.05?:_____
Reject H0 at α=.01?:_____
95% CL: E=_____ CI:[_____,______] Contains 0?:____ Reject H0?:___
99% CL: E=_____ CI:[_____,______] Contains 0?:____ Reject H0?:___