A hotel chain recently surveyed 300 new customers and asked them to rate their overall satisfaction with their recent hotel stay. The survey estimated a mean satisfaction of 7 with a standard deviation of 1. If the data are normal distributed, approximately how many new customers gave the hotel a rating of 6,7, or 8? 150 175 O 200 285

Respuesta :

Answer: 200

Step-by-step explanation:

Given : A hotel chain recently surveyed 300 new customers and asked them to rate their overall satisfaction with their recent hotel stay.

The survey estimated a mean satisfaction [tex]\mu=7[/tex] with a standard deviation [tex]\sigma=1[/tex].

Let x represents the rating given by customer.

Using formula , [tex]z=\dfrac{x-\mu}{\sigma}[/tex].

For x = 6, z= -1

For x= 8 , z=1

The probability that new customers gave the hotel a rating of 6,7, or 8 will be :-

[tex]P(6\leq x\leq8)=P(-1\leq z\leq1)=P(z\leq1)-P(z\leq-1)\\\\=P(z\leq1)-(1-P(z\leq1))\\\\=2P(z\leq1)-1\\\\=2(0.8413447)-1=0.6826894\approx0.68[/tex]

The number of new customers gave the hotel a rating of 6,7, or 8 will be :-

[tex]0.68\times300=204\approx200[/tex] [Rounded to the nearest tens]

Hence, the approximate number of new customers gave the hotel a rating of 6,7, or 8  =200