Question

the standard deviation of duration times in seconds of the old faithful geyser is less than 40 sec. identify the null hypothesis and alternative hypothesis in symbolic form

Answer 1

this is a left tailed test

Null hypothesis,
`H_(0) :` σ = 40 seconds

Alternate hypothesis,
`H_(a) :` σ < 40 seconds.

Explanation:

i) the standard deviation of duration times in seconds of the old faithful geyser is less than 40 sec. identify the null hypothesis and alternative hypothesis in symbolic form

ii) this is a left tailed test

Null hypothesis,
`H_(0) :` σ = 40 seconds

Alternate hypothesis,
`H_(a) :` σ < 40 seconds.