Kwingxelo yeveki ye-RKI yomhla we-11.11.2021 idweliswe kwiphepha lama- 22 ukuba \(36\%\) yezigulane ze-corona ezingaphezulu kweminyaka engama-60 kwiyunithi yokhathalelo olunzima sele zigonywe ngokupheleleyo. Kweli qela lobudala, \(87\%\) bagonywe ngokupheleleyo ngeli xesha ngexesha (jonga iphe. 18).
Ingayiyo:
- \(G\): Abantu abangaphezu kweminyaka engama-60 bayagonywa
- \(U\): Abantu abangaphezu kweminyaka engama-60 abagonywa
- \(I\): Abantu abangaphezu kweminyaka engama-60 bakukhathalelo olunzima
Ngoku kunjalo
$$P(G) = 0,87 \wedge P(U) = 0,13.$$
Kwakhona kunjalo
$$P(G|I) = \frac{P(G \cap I)}{P(I)} = 0,36 \wedge P(U|I) = \frac{P(U \cap I)}{P(I)} = 0,64.$$
Kunjalo ke
$$P(G \cap I) = 0,36 \cdot P(I) \wedge P(U \cap I) = 0,64 \cdot P(I)$$
kwaye ngenxa yokuba
$$P(I|U) = \frac{P(I \cap U)}{P(U)} = \frac{P(U \cap I)}{P(U)} = \frac{0,64 \cdot P(I)}{0,13} \Rightarrow P(I) = \frac{0,13 \cdot P(I|U)}{0,64}.$$
Iyalandela
$$P(I|G) = \frac{P(I \cap G)}{P(G)} = \frac{P(G \cap I)}{P(G)} = \frac{0,36 \cdot P(I)}{0,87} = \frac{0,36 \cdot \frac{0,13 \cdot P(I|U)}{0,64}}{0,87} = \frac{0,36 \cdot 0,13}{0,64 \cdot 0,87} \cdot P(I|U) \approx 0,08 \cdot P(I|U).$$
Oku kuthetha ukuba umngcipheko wabantu abaneminyaka engaphezu kwama-60 abagqibela bekwigumbi labagula kakhulu ungaphezulu ngokuphindwe ka-10 kwabo bangakhange bagonywe kunabo bagonyiweyo.