In 2003, Forster and Solomon (Observations of a weekend effect in diurnal temperature range, PNAS, [ http://www.pnas.org/content/100/20/11225.full ]) reported: we find evidence of a weekly cycle in diurnal temperature range (DTR) for many stations in the United States, Mexico, Japan, and China.
The total cost to have a concrete retaining wall installed will be a combination of material and labor prices. For a basic wall you can expect to pay between $30 and $40 per square foot.
According to our concrete slab material estimator, the average minimum cost per square foot of a concrete slab is $1.36 and the maximum is $1.88. By comparison, the price per square foot for a cement slab is $5.50. Just know that even if you do not hire a pro, there are additional costs that come with all concrete slab projects.