Fixed Wrong Integral from SingleContinuousPSpace

[Smit-create]

Fixes Wrong Integral from SingleContinuousPSpace.

References to other Issues or PRs

Fixes #10076

Brief description of what is fixed or changed

Before:

>>> from sympy import Symbol
>>> from sympy.stats.crv_types import NormalDistribution
>>> from sympy.stats.crv import SingleContinuousPSpace
>>> x = Symbol('x')
>>> a = SingleContinuousPSpace(x, NormalDistribution(2, 4))
>>> a.probability(x < 1)
Integral(0, (_z, -oo, 0))

After:

>>> from sympy import Symbol
>>> from sympy.stats.crv_types import NormalDistribution
>>> from sympy.stats.crv import SingleContinuousPSpace
>>> x = Symbol('x')
>>> a = SingleContinuousPSpace(x, NormalDistribution(2, 4))
>>> a.probability(x < 1)
Integral(sqrt(2)*exp(-(_z - 2)**2/32)/(8*sqrt(pi)), (_z, -oo, 1))

Other comments

Release Notes

• stats
  • Fixes Wrong Integral result from SingleContinuousPSpace

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• stats
  • Fixes Wrong Integral result from SingleContinuousPSpace (#18336 by @Smit-create)

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<!-- Your title above should be a short description of what
was changed. Do not include the issue number in the title. -->
Fixes Wrong Integral from SingleContinuousPSpace.
#### References to other Issues or PRs
<!-- If this pull request fixes an issue, write "Fixes #NNNN" in that exact
format, e.g. "Fixes #1234". See
https://github.com/blog/1506-closing-issues-via-pull-requests . Please also
write a comment on that issue linking back to this pull request once it is
open. -->
Fixes #10076

#### Brief description of what is fixed or changed
Before:
```
>>> from sympy import Symbol
>>> from sympy.stats.crv_types import NormalDistribution
>>> from sympy.stats.crv import SingleContinuousPSpace
>>> x = Symbol('x')
>>> a = SingleContinuousPSpace(x, NormalDistribution(2, 4))
>>> a.probability(x < 1)
Integral(0, (_z, -oo, 0))

```
After:
```
>>> from sympy import Symbol
>>> from sympy.stats.crv_types import NormalDistribution
>>> from sympy.stats.crv import SingleContinuousPSpace
>>> x = Symbol('x')
>>> a = SingleContinuousPSpace(x, NormalDistribution(2, 4))
>>> a.probability(x < 1)
Integral(sqrt(2)*exp(-(_z - 2)**2/32)/(8*sqrt(pi)), (_z, -oo, 1))
```
#### Other comments


#### Release Notes

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https://github.com/sympy/sympy/wiki/Writing-Release-Notes for more information
on how to write release notes. The bot will check your release notes
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<!-- BEGIN RELEASE NOTES -->
* stats
  * Fixes Wrong Integral result from SingleContinuousPSpace
<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

[Smit-create]

@oscarbenjamin @czgdp1807 Does it seems good now?it is also applicable to all the continuous distributions.

[Smit-create]

@czgdp1807 @oscarbenjamin Is it ready to merge?

[oscarbenjamin]

I left a couple of minor comments. This looks fine to me but I don't know the stats part of the codebase very well.

[Smit-create]

@czgdp1807 Updated with suggested changes, Is this now ready to merge?

[czgdp1807]

LGTM. Will merge if no one objects for some time. Until then you can merge master and push here(for double surety).

[codecov]

Codecov Report

Merging #18336 into master will increase coverage by 0.261%.
The diff coverage is 81.701%.

@@              Coverage Diff              @@
##            master    #18336       +/-   ##
=============================================
+ Coverage   75.031%   75.293%   +0.261%     
=============================================
  Files          649       633       -16     
  Lines       167370    166922      -448     
  Branches     39421     39391       -30     
=============================================
+ Hits        125581    125682      +101     
+ Misses       36249     35705      -544     
+ Partials      5540      5535        -5