Three capacitors of capacitances \( 25 \, \mu \text{F} \), \( 30 \, \mu \text{F} \) and \( 45 \, \mu \text{F} \) are connected in parallel to a supply of \( 100 \, \text{V} \). Energy stored in the above combination is \( E \). When these capacitors are connected in series to the same supply, the stored energy is \( \frac{9}{x} E \). The value of \( x \) is __________.
