I did add StatsBase as instructed, but still fail:
$ julia
_
_ _ _(_)_ | A fresh approach to technical computing
(_) | (_) (_) | Documentation: https://docs.julialang.org
_ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
| | | | | | |/ _` | |
| | |_| | | | (_| | | Version 0.7.0 (2018-08-08 06:46 UTC)
_/ |\__'_|_|_|\__'_| | Official http://julialang.org/ release
|__/ | x86_64-pc-linux-gnu
julia> x=[1:50;]
50-element Array{Int64,1}:
1
2
3
4
5
6
7
8
9
⋮
42
43
44
45
46
47
48
49
50
julia> y=rand(50)
50-element Array{Float64,1}:
0.7617834396266145
0.6379048953534547
0.40021790841211335
0.9545693579078784
0.2513947682411304
0.25536026947148516
0.4629605227317848
0.3377036794505843
0.46101256333717755
⋮
0.15851794551099307
0.3534059797211213
0.9757071421312202
0.07445292153533645
0.5241411433580192
0.41539986402813156
0.04729731573022877
0.7069441222457196
0.24777203771345424
julia> using StatsBase
julia> linreg(x, y)
ERROR: linreg has been moved to the package StatsBase.jl.
Run `Pkg.add("StatsBase")` to install it, restart Julia,
and then run `using StatsBase` to load it.
Stacktrace:
[1] error(::String) at ./error.jl:33
[2] #linreg#810(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::Function, ::Array{Int64,1}, ::Vararg{Any,N} where N) at ./deprecated.jl:150
[3] linreg(::Array{Int64,1}, ::Vararg{Any,N} where N) at ./deprecated.jl:150
[4] top-level scope at none:0