Model Reports Relevant to Assignment 2
In this document you’ll find all of the model reports from the text which are relevant to Assignment 2
Independent samples t-test
A researcher hypothesised that the blood cholesterol levels of people who do not exercise regularly would be higher than those of regular exercisers.
In a random sample of 78 adults, the average blood cholesterol level of the non-exercisers
(247.65mg/dL,
s=33.44mg/dL,
n=43) was higher than the average blood cholesterol level of the people who exercise regularly (189.06mg/dL,
s=35.96mg/dL,
n=35), and an independent samples t-test shows that this difference in mean blood cholesterol level is significant,
t(76)=7.44,
pAs expected, the blood cholesterol levels of non-exercisers are higher than for those people who exercise regularly.
A junior athletics coach hypothesised that the time taken to run 25 metres (in seconds) by children from Easterly Primary School would be shorter than for children from Northhaven Primary School.
In a random sample of 50 Year 8 students, the mean time taken to run 25 metres by the Easterly children (12.32 sec,
s=4.25 sec,
n=25) was more than the mean time taken to run 25 metres by the Northhaven children (8.20 sec,
s=3.97 sec,
n=25), and an independent samples t-test shows that this difference in mean time taken to run 25 metres is significant,
t(48)=3.54,
p=.001. The 95% confidence interval indicates that, on average, Easterly children run this distance between 2 and 6 less seconds slower than Northhaven children.
Contrary to expectations, the time taken to run 25 metres by children from Easterly Primary School is longer than for children from Northhaven Primary School.
It was suggested that drivers in the Northern suburbs use more fuel than those in the Western suburbs.
In a sample of 100 drivers, the average fuel consumption for those from the Northern suburbs
(litres, litres, ) was greater than the average fuel consumption for drivers from the Western suburbs (litres, litres, ). However, an independent samples t-test shows that this difference in mean fuel consumption is not significant, ,
p=.105.
There is insufficient evidence to suggest that fuel consumption is higher for drivers in the Northern suburbs than for drivers in the Western suburbs.
Paired samples t-test
It was hypothesised that hypnosis would help reduce the number of cigarettes smoked.
In a sample of 20 smokers, on average the number of cigarettes smoked in the week after hypnosis was lower (=143.70,
s=46.75) than the number of cigarettes smoked in the week before hypnosis (=180.70,
s=64.36). A paired samples t-test shows that this difference in mean number of cigarettes smoked (,
s
d
=27.83) is significant,
t(19)=5.95,
pAs expected, hypnosis reduces the number of cigarettes smoked.
It was hypothesised that tourists visiting the zoo would spend longer viewing the primates than they would viewing the reptiles.
In a sample of 20 tourists, on average, the time spent viewing the primates (=62.56min,
s=12.63 min) was less than the time they spent viewing the reptiles (=72.49min,
s=17.48min), and a paired samples t-test shows that this difference in mean viewing time (
d
=9.93 min,
sd
=15.07 min) is significant,
t(19)=2.95,
p=.008. The 95% confidence interval indicates that, on average, tourists visiting the zoo spend between 3 and 17 minutes less viewing the primates than viewing the reptiles.
Contrary to expectations, tourists visiting the zoo spend less time viewing the primates than they spend viewing the reptiles.
It was hypothesised that the blood cholesterol levels in people with heart disease could be lowered by introducing plant sterols into the diet.
In a random sample of 26 people with heart disease, on average, blood cholesterol levels were lower after sterols were added to the diet (=255.45md/dl,
s=40.30mg/dl) than before (=260.60mg/dl,
s=34.13mg/dl). However, a paired samples t-test shows that this difference in mean blood cholesterol levels (=5.15mg/dl,
sd=18.66mg/dl) is not significant,
t(25)=1.41,
p=.172.
There is insufficient evidence to conclude that there is a difference in the blood cholesterol levels after the introduction of sterols into the diet.
Model Reports Relevant to Assignment 2
In this document you’ll find all of the model reports from the text which are relevant to Assignment 2
Independent samples t-test
A researcher hypothesised that the blood cholesterol levels of people who do not exercise regularly would be higher than those of regular exercisers.
In a random sample of 78 adults, the average blood cholesterol level of the non-exercisers
(247.65mg/dL,
s=33.44mg/dL,
n=43) was higher than the average blood cholesterol level of the people who exercise regularly (189.06mg/dL,
s=35.96mg/dL,
n=35), and an independent samples t-test shows that this difference in mean blood cholesterol level is significant,
t(76)=7.44,
pAs expected, the blood cholesterol levels of non-exercisers are higher than for those people who exercise regularly.
A junior athletics coach hypothesised that the time taken to run 25 metres (in seconds) by children from Easterly Primary School would be shorter than for children from Northhaven Primary School.
In a random sample of 50 Year 8 students, the mean time taken to run 25 metres by the Easterly children (12.32 sec,
s=4.25 sec,
n=25) was more than the mean time taken to run 25 metres by the Northhaven children (8.20 sec,
s=3.97 sec,
n=25), and an independent samples t-test shows that this difference in mean time taken to run 25 metres is significant,
t(48)=3.54,
p=.001. The 95% confidence interval indicates that, on average, Easterly children run this distance between 2 and 6 less seconds slower than Northhaven children.
Contrary to expectations, the time taken to run 25 metres by children from Easterly Primary School is longer than for children from Northhaven Primary School.
It was suggested that drivers in the Northern suburbs use more fuel than those in the Western suburbs.
In a sample of 100 drivers, the average fuel consumption for those from the Northern suburbs
(litres, litres, ) was greater than the average fuel consumption for drivers from the Western suburbs (litres, litres, ). However, an independent samples t-test shows that this difference in mean fuel consumption is not significant, ,
p=.105.
There is insufficient evidence to suggest that fuel consumption is higher for drivers in the Northern suburbs than for drivers in the Western suburbs.
Paired samples t-test
It was hypothesised that hypnosis would help reduce the number of cigarettes smoked.
In a sample of 20 smokers, on average the number of cigarettes smoked in the week after hypnosis was lower (=143.70,
s=46.75) than the number of cigarettes smoked in the week before hypnosis (=180.70,
s=64.36). A paired samples t-test shows that this difference in mean number of cigarettes smoked (,
s
d
=27.83) is significant,
t(19)=5.95,
pAs expected, hypnosis reduces the number of cigarettes smoked.
It was hypothesised that tourists visiting the zoo would spend longer viewing the primates than they would viewing the reptiles.
In a sample of 20 tourists, on average, the time spent viewing the primates (=62.56min,
s=12.63 min) was less than the time they spent viewing the reptiles (=72.49min,
s=17.48min), and a paired samples t-test shows that this difference in mean viewing time (
d
=9.93 min,
sd
=15.07 min) is significant,
t(19)=2.95,
p=.008. The 95% confidence interval indicates that, on average, tourists visiting the zoo spend between 3 and 17 minutes less viewing the primates than viewing the reptiles.
Contrary to expectations, tourists visiting the zoo spend less time viewing the primates than they spend viewing the reptiles.
It was hypothesised that the blood cholesterol levels in people with heart disease could be lowered by introducing plant sterols into the diet.
In a random sample of 26 people with heart disease, on average, blood cholesterol levels were lower after sterols were added to the diet (=255.45md/dl,
s=40.30mg/dl) than before (=260.60mg/dl,
s=34.13mg/dl). However, a paired samples t-test shows that this difference in mean blood cholesterol levels (=5.15mg/dl,
sd=18.66mg/dl) is not significant,
t(25)=1.41,
p=.172.
There is insufficient evidence to conclude that there is a difference in the blood cholesterol levels after the introduction of sterols into the diet.