Lemma
MediumSampling distributions
OpenStax, Introductory Statistics 2e §7.3 Using the Central Limit Theorem · Exercise 25 · Statistics · Sampling distributions

Using the Central Limit Theorem · Exercise 25

The attention span of a two-year-old is exponentially distributed with a mean of about eight minutes. Suppose we randomly survey 60 two-year-olds.

(a) In words, Χ = _______
(b) Χ ~ _____(_____,_____)
(c) In words, = ____________
(d) ~ _____(_____,_____)
(e) Before doing any calculations, which do you think will be higher? Explain why.
(a) The probability that an individual attention span is less than ten minutes.
(b) The probability that the average attention span for the 60 children is less than ten minutes?
(f) Calculate the probabilities in part e.
(g) Explain why the distribution for is not exponential.

Its source prints no answer for this problem, so there's nothing to check against.

~8 minWritten answer · check your work with Lemma

OpenStax, Introductory Statistics 2e · §7.3 Using the Central Limit Theorem · Exercise 25

Stuck? A gentle nudge

No hints for this one.

Something off?
Workspace
Your working

Check your full solution

Attach photos of your pages (up to 3) or one PDF — or check what you typed above. Lemma reads the work and verifies the reasoning, not just the answer.

Your first check today doesn't need an account.

Your photos and PDFs are read once and not stored — only the transcription is kept.