An experiment was conducted to examine the effect of age on heart rate when a su

Question

An experiment was conducted to examine the effect of age on heart rate when a subject performs a specific amount of exercise. Ten male subjects were randomly selected from four age groups: (10-19), (20-39), (40-59), and (60-69). Each subject walked a treadmill at a fixed grade for a period of 12-minutes, and the increase in heart rate (the difference before and after exercise) was recorded (in beats per minute). The Data is shown below

a). Does the data provide sufficient evidence to indicate a difference in mean increase in heart rate among the four age groups using = .025?

b). If appropriate, determine which age groups differ in mean increase in heart rate. Briefly explain.

c). If appropriate, determine if there is evidence of a difference in the variation in heart rates among the four age groups? Briefly explain.

Age 10 -19 20 - 39 40 - 59 60 -69 29 24 37 28 33 27 25 29 26 33 22 34 27 31 33 36 39 21 28 21 35 28 26 20 33 24 30 25 29 34 34 24 36 21 27 33 22 32 33 32

Explanation / Answer

a) Here as we have four different and their heart rate we can use one way ANOVA to compute whether there is a signficant difference in mean increase in heart rate among the four age groups.

So the descriptive statistics are

N   Mean   Std. Deviation 95% Confidence Interval for Mean
Lower Bound   Upper Bound      
1.00   10   30.9000   5.19508 27.1837   34.6163
2.00   10   27.5000   4.88194 24.0077   30.9923
3.00   10   29.5000   4.69633 26.1404   32.8596
4.00   10   28.2000   5.57375 24.2128   32.1872
Total   40   29.0250   5.07122 27.4031   30.6469

where 1:10-19, 2:20-39, 3:40-59, 4:60-69

Here variances of the group are eqal.(Applied leves eqality of variance,pvalue>0.05)

When ANOVA is applies we got the following result

ANOVA                  

Sum of Squares   df Mean Square   F   Sig.
Between Groups 67.475 3 22.492 .866   .468
Within Groups 935.500 36 25.986      

Here pvalue=0.468 which is > 0.025

Hence there is no significance difference in the mean increase in the heart rate.

b). Here there is no significance difference in the mean increase in the heart rate hence we can't determine which age groups differ in mean increase in heart rate.

c) we have applied levence test to determine the variation in the heart rates among the four age groups.

Test of Homogeneity of Variances          

Levene Statistic   df1   df2   Sig.
.147 3   36   .931

Levence pvalue=0.931>0.05

Hence there is no  evidence of a difference in the variation in heart rates among the four age groups.

  
  

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