Determine the probability

Dwelling is experiencing an increasing need for dialogue by phone and is continuallyworking on assessment of staffing. Assumingthat the number of phonecalls is Poissondistributed with mean of 10 calls per.30 minutes.

2.1

Determine the probability of more than 12 calls in the course of 30 minutes.

2.2

Determine the probability of between 15 and 25 (bothinclusive). Calls during an hour.

Dwelling’s website is under continuousimprovement, and for this purpose, usersareable to evaluate the website on a continuousscale from 0-100, where 100 is the best (assessmentindex).

The management of Dwellingconsider it unacceptableif the average assessmentindex is below 75

During the pastweek, 20 customersrated website. The resultsareshown in Table 1

Table 1 evaluationindex from 20 randomlyselectedusers of the website.

Assumingthese 20 assessmentscanbeconsidered a random sample, pleasereplybelow.

2.3

Check ifvurdingsindeksetcanbeassumed to follow a normal distribution.

2.4

Based on youranswer to question 2.3 please test at the 5% level on the average assessmentindex is below 75

2.5

Rate signifikansniveauets affectyourconclusion in question 2.4