1. A researcher compared 141 babies who developed cerebral palsy to a control group of (control) babies made up from the babies who appeared immediately after each cerebral palsy case in the hospital delivery book. The corresponding hospital notes were reviewed by a researcher, who was blind to the baby's outcome, with respect to medical staff response to signs of fetal stress. Failure to respond to signs of fetal distress by the medical staff was noted in 25.8% of the cerebral palsy babies and in 7.1 % of the next delivery control: a difference of 18.7 %. This difference had standard error of 4.2 % and a 95% CI was 10.5 to 26.9 %. Let the level of significance is 0.05.
(1) What can we conclude from the 95% CI?
(2) The two-tailed p-value was 0.028. Test if there is a difference between the cerebral palsy babies and the delivery book control.
(3) Using the two-tailed p-value of 0.028, test if the percentage of deliveries where there was a failure to respond to signs of foetal distress in the cerebral palsy babies is greater than that of the delivery book control.
2. The percent body fat data was collected from males age 65 or older. SPSS output is given below. Use alpha = 0.10.
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One-Sample Statistics
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|
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N
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Mean
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Std. Deviation
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Std. Error Mean
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fat
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21
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25.7381
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6.89815
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1.5053
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One-Sample Test
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Test Value = 28
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|
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t
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df
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Sig. (2-tailed)
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Mean Difference
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95% Confidence Interval of the Difference
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|
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Lower
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Upper
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fat
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-3.812
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20
|
.002
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5.73810
|
2.5981
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8.8781
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(1) Test if the mean body fat is 28or not for males age 65 or older.
(2) Test if the mean body fat is less than 28 for males age 65 or older.
3. A study on birth weight provided the following data (in ounces) in 12 newborns to test if the average birth weight is 100 ounces. Assume that the underline distribution is a normal. Use alpha = 0.05. SPSS output should be attached for the whole credit.
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112
|
111
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107
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119
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92
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80
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81
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84
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118
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106
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103
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94
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One-Sample Statistics
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N
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Mean
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Std. Deviation
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Std. Error Mean
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VAR00001
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12
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100.5833
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14.00298
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4.04231
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One-Sample Test
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Test Value = 0
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t
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df
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Sig. (2-tailed)
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Mean Difference
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95% Confidence Interval of the Difference
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Lower
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Upper
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VAR00001
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24.883
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11
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.000
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100.58333
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91.6863
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109.4804
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4. A UK study of factors affecting the outcome of pregnancy among 150 women reported that the 54 women had overall incidence of preterm births. Test if the population proportion of having overall incidence of preterm births is less than 50% with α = 0.05. SPSS output should be attached for the whole credit.
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Binomial Test
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|
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Category
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N
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Observed Prop.
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Test Prop.
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Exact Sig. (2-tailed)
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count
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Group 1
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150.00
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150
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.74
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.50
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.000
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Group 2
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54.00
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54
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.26
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|
|
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Total
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204
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1.00
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