At Westonci.ca, we connect you with the answers you need, thanks to our active and informed community. Connect with a community of experts ready to help you find accurate solutions to your questions quickly and efficiently. Explore comprehensive solutions to your questions from knowledgeable professionals across various fields on our platform.

The maintenance department at the main campus of a large state university receives daily requests to replace fluorecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 47 and a standard deviation of 7. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 47 and 68

Sagot :

Answer:

[tex]P(-2<Z<2)=95\%[/tex]

Step-by-step explanation:

From question we are told that

Sample mean [tex]\=x= 47[/tex]

Standard deviation [tex]\sigma =7[/tex]

Generally the  X -Normal is given as

      [tex]Z=\frac{x-\=x}{\sigma}[/tex]

      [tex]Z=\frac{x-47}{9}[/tex]

Analyzing the range

    [tex]P(47<x<65) = P(0< z<2.00)[/tex]

    [tex]P(47<x<65) = 95/2[/tex]

   [tex]P(47<x<65) = 47.5\%[/tex]

Mathematically

[tex]Z_1 =\frac{47-47}{9} =0[/tex]

[tex]Z_2 =\frac{65-47}{9} =2[/tex]

Empirical rule shows that

[tex]P(-2<Z<2)=95\%[/tex]