Examples
Examples
Try the starting example
- Sample mean
- 100
- Known population standard deviation
- 10
- Sample size
- 100
- Chosen normal critical z
- 1.96
- Lower confidence bound
- 98.04
- Upper confidence bound
- 101.96
Try another scenario
- Sample mean
- 110.00000000000001
- Known population standard deviation
- 10
- Sample size
- 100
- Chosen normal critical z
- 1.96
- Lower confidence bound
- 108.04
- Upper confidence bound
- 111.96
Calculation method
Calculation method
Lower confidence bound
a-d × b ÷ sqrt(c)
Upper confidence bound
a+d × b ÷ sqrt(c)
Symbols and units
- a
- Sample mean
- b
- Known population standard deviation
- c
- Sample size
- d
- Chosen normal critical z
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Calculation steps and notation
sqrt(x) is the non-negative square root of x.
Assumptions & limits
Assumptions & limits
- Normal interval using a known population standard deviation and user-supplied critical z. This is not a t interval for an estimated standard deviation.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
Background reading; this does not imply endorsement or independent review of SumFizz.