Answer the following question:

Headings for a variance analysis of FMOH costs:

$-1.$ Actuals Costs Incurred, $2.$ Same Budgeted Lump Sum $($as in Static Budget$)$ Regardless of Output Level, $3.$ Flexible Budget: Same Budgeted Lump Sum $($as in Static Budget$)$ Regardless of Output Level, $4.$ Allocated Budgeted Input Qty$.$ Allowed for Actual Output x Budgeted Rate

$-*2$ and $3$ are the same number

Headings for rate and efficiency variances for variable MOH:

$-1.$ Actual Costs Incurred, $2.$ Actual Input x Budgeted Rate, $3.$ Flexible Budget: Budgeted Input Allowed for Actual Output x Budgeted Rate

Headings for rate and production$-$volume variances for fixed MOH:

$-1.$ Actual Costs Incurred, $2.$ Flexible Budget: Same Budgeted Lump Sum $($as in Static Budget$)$ Regardless of Output Level, $3.$ Allocated: Budgeted Input Allowed for Actual Output x Budgeted Rate

Why is there $$Same Budgeted Lump Sum $($as in Static Budget$)$ Regardless of Output Level$$ for variance analysis of FMOH costs but not rate and production$-$volume variances for fixed MOH?

In the first situation we have rate variance, never a variance, production$-$volume variance but for rate and production$-$volume variances for fixed MOH we have rate variance and efficiency variance only? Why?

Are there certain headings for each situation for example FMOH and VMOH? Please explain.