I need help with this it’s for a quiz

The frequency table shows the results of a survey comparing the number of beach towels sold for full price and at a discount during each of the three summer months. the store owner converts the frequency table to a conditional relative frequency table by row. which value should he use for x? round to the nearest hundredth. 0.89 0.90 0.92 0.96

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

Extra points! find the missing dimension! need asap