Adults Who Stutter: Responses to Cognitive Stress published inthe Journal of Spe

Adults Who Stutter: Responses to Cognitive Stress published inthe Journal of Speech and Hearing Research in 1994 reported thatspeech rate in words per minute for 9 stutterers under conditionsof stress had mean 52.6 and standard deviation 3.2 a. Use the factthat the t multiplier for 8 degrees of freedom at 99% confidence is3.36 to construct a 99% confidence interval for mean speech rate ofall stutterers under conditions of stress. b. If a lower level ofconfidence were desired would the interval be wider or narrower?c. If the standard deviation has been larger than 3.2 would theinterval be wider or narrower? d. If the sample size had beensmaller than 9 would the interval be wider or narrower? e. If 3.2were known population standard deviation instead of samplestandard deviation would the interval be wider or narrower?