Introduction
Hypothesis testing is crucial in statistics by facilitating the inference-making process regarding particular populations. The procedure usually begins with formulating hypotheses (Weng &Mandrinos, 2020). After formulating the hypotheses, specific criteria are established to determine whether to accept or reject the null hypothesis. In most instances, alpha (α), a significance level is selected. Some of the alpha (α) are 0.1, 0.05, or 0.01.). Consequently, appropriate test statistics are chosen. Various test statistics, encompassing ANOVA, chi-square tests, t-tests, and z-tests, among others, are available for this purpose ((Weng &Mandrinos, 2020). This study opted for histogram as the test statistics to validate the hypotheses the following hypotheses:
Null hypothesis (H0): The mean age of women giving birth is 37.
Alternative hypothesis (H1): The mean age of women giving birth is not 37.
Furthermore, the mean (μ = u0 = 37 years old), was tested to validate the null and alternative hypotheses. The data was obtained from Gestation Demographics SEU dataset, which aided in calculating the mean (calculated mean using Excel= 27.26 years old). Moreover, histogram was developed based on the calculated mean (27.26 years old). As a result, a class of 10 was used. For this reason, the data was between 15 and 55 years old.
Discussion
The data illustrates that the majority of women giving birth are clustered within the 15-34 age bracket, evident from the notably higher frequencies observed in the 25-44 and 15-24 age groups compared to other age categories (Figure A). Additionally, there is a discernible decline in frequency as age progresses beyond the 35-44 age category. Consequently, based on this dataset, the histogram is expected to exhibit a right-skewed distribution (positively skewed), reflecting the reduced occurrence of births among older age groups relative to younger ones. Notably, the histogram displays a peak in the 25-34 age range, with frequencies diminishing as one proceeds towards older age segments.
Figure A: Age distribution of women giving birth to their first child
The histogram displays a right-skewed pattern, with a higher proportion of women giving birth observed in the younger age brackets (25-34) and a decreased frequency in the older age categories (45-55). Moreover, there is a prominent peak in the distribution around the 25-34 age group, which serves as the mode of the distribution. Additionally, the histogram’s tail extends towards the right, indicating a diminished occurrence of births among older age groups. Furthermore, the mean value of 27.26 aligns closely with the distribution’s peak, specifically around the 25-34 age range. Thus, this mean provides a more accurate representation of the data’s central tendency.
Conversely, the mean value of 37 lies higher and is situated within the age brackets of 35-44 and 45-55, where the frequencies are comparatively lower. Consequently, this mean does not accurately reflect the central tendency of the data, unlike the mean of 27.26. This discrepancy leads to the rejection of the null hypothesis (H0), which posits that the mean age of women giving birth is 37 years old.
Typically, women in their late teens and twenties experience optimal fertility levels. As age advances, fertility tends to decrease, especially after reaching the age of 35, which aligns with the current discovery. Additionally, younger women tend to exhibit more regular menstrual cycles and higher egg quality, enhancing the chances of conception (Lindell Pettersson, 2022). Generally, younger women enjoy better overall health, with fewer underlying health issues that could influence fertility or pregnancy outcomes. Conversely, older women may have existing medical conditions that could adversely affect fertility or heighten the likelihood of pregnancy complications (Nega et al., 2023).
Conclusion
The histogram illustrating the distribution of women giving birth exhibits a distinct right-skewed pattern, indicating a higher incidence of births among younger age brackets (15-34), with a gradual decline in frequency as age progresses, particularly noticeable in older age groups (35-55). The peak of the distribution, centered on the 25-34 age group, highlights a pronounced surge in birth rates within this age range. Furthermore, the elongated tail of the histogram towards the right signifies a significant reduction in birth frequencies among older women. Moreover, in terms of calculated means, the value of 27.26 closely corresponds to the distribution’s peak, offering a more precise depiction of the data’s central tendency. On the contrary, the mean of 37 falls within age groups with lower frequencies, rendering it less suitable as a measure of central tendency. Therefore, the null hypothesis (H0) positing a mean age of 37 for women giving birth is refuted, while the alternative hypothesis is upheld. This emphasizes that the mean age of women giving birth is more accurately estimated at 27.26 years old, as indicated by the observed distribution.
References
Lindell Pettersson, M. (2022). Women giving birth at an advanced age and their children: obstetric and neonatal outcomes, health and social support. Linköping University Electronic Press, Linköping University Electronic Press.
Nega, M. A., Assefa, H. K., Mengistu, M. Y., & Kassahun, A. G. (2023). Determinants of time to first marriage and birth intervals among women of child bearing age in Dabat Health and demographic surveillance system site, Northwest Ethiopia. PLoS One, 18(2), 1-17. https://doi.org/10.1371/journal.pone.0281997
Weng, M. L., & Mandrinos, S. (2020). Incidental findings on multimodel comparison, hypothesis testing error, and its solution: The case of information, knowledge, and career pursuit. Australasian Journal of Information Systems, 24https://doi.org/10.3127/ajis.v24i0.2555
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