I was wondering if CSS gurus could answer my questions about the code below which I found on the www.

1. What does 1.5 mean in the following line?

   font:100%/1.5 Cambria, Georgia, serif; /* 16px */
   

2. In the line below, I kind of have the same question ( what does 1.1429 mean), but at the same time I want to know why this figure equals to 32px for the author of the code(see his CSS comments)

   font:bold 1.75em/1.1429 'Proxima Nova Bold',sans-serif; /* 28px/32px */

Thank you so much for your help. This is the full code:

body {
    color:#333;
    font:100%/1.5 Cambria, Georgia, serif; /* 16px */
}



h1 {
    color:#2c1c16;
    font:bold 1.75em/1.1429 'Proxima Nova Bold',sans-serif; /* 28px/32px */
    margin:0.8571em 0 0; /* 24px 0 0 */
}