10.5 Covariance and Correlation Exercise -- Task 5 --> "Psych" package

Hello, I am unable to call the describe(product$Price) function because I cannot install the "psych package"  

1. When I use the code:install.packages("psych") -- I get the following error:

"Warning in install.packages : dependency ‘mnormt’ is not available"       2.  Knock-on effect, when I try  to call library( psych)-- I get the following error: "Error in library(psych) : there is no package called ‘psych’"   As A result I cannot use the describe(.....) function. Any guidance would be greatly appreciated, thanks!