Need help with this question please--Q3

For what values of b will f(x)= logbx be a decreasing function? (16 )

What does the relationship between the mean and median reveal about the shape of the data

Acompany that manufactures and sells guitars made changes in their product range. from the start they had 20 models. then they reduced the number of models to 15. as a result, the company enjoyed a 10% increase in turnover. - how much did the stock level change? in (%)