Question

QUESTION 1:

Researchers claim that women speak significantly more words per day than men. One estimate is that a woman uses about 20,000 words per day while a man uses about 7,000. To investigate such claims, one study used a special device to record the conversations of male and female university students over a four- day period. From these recordings, the daily word count of the 20 men in the study was determined. Here are their daily word counts:

28401	10093	15933	21682	37778
10573	12881	11063	17791	13180
8910	6495	8145	7018	4430
10050	4000	12646	10971	5247

What value we should remove from observation for applying t procedures?

A 90% confidence interval (±±10) for the mean number of words per day of men at this university is from  to  words.

Is there evidence at the 10% level that the mean number of words per day of men at this university differs from 9000?

No

Yes

QUESTION 2:

Cola makers test new recipes for loss of sweetness during storage. Trained tasters rate the sweetness before and after storage. Here are the sweetness losses ( sweetness before storage minus sweetness after storage) found by 10 tasters for one new cola recipe:

1.8	0.4	0.6	2	-0.6
2.4	-1.2	1.1	1.2	2.2

Take the data from these 10 carefully trained tasters as an SRS from a large population of all trained tasters.

Is there evidence at the 5% level that the cola lost sweetness? If the cola has not lost sweetness, the ratings after should be the same as before it was stored.

The test statisic is t =  (±±0.001)

Yes

No

Answer 1