Question

an electric company producing electric bulbs ,has packed 100bulbs in each box .some bulbs from 16 such boxes are tested defective the information of number of defective bulbs in 16 boxes given below

Answer 1

1. one as the max. no. of defective bulbs are 8 to 10 and only one box bears such a large quantity of defective bulbs

2. to find mean firstly find xi ( class mark = upper limit + lower limit)

let no. of boxes be fi

now multiply fi × xi

add all the products

then use the formula i.e. mean =

sum of fixi ÷ sum of fi

sol. interval fi xi fixi

0-2 3 1 3

2-4 4 3 12

4-6 5 5 25

6-8 3 7 21

8-10 1 9 9

16 70

mean = 70÷16= 4.375 bulbs

3. may be its ans. is 4 / 16 = 1/4

4. 1/16

I m not sure about my answers.

but hope it will help uuu

Answer 2

Answer:

Number of box contains maximum defective bulbs = 1

Mean of defective bulbs = 4.375

Probability to select box with 2-4 defective bulbs = 1/4

Probability to select box with maximum defective bulbs = 1/16

 Step-by-step explanation:

• Number of boxes have maximum defective bulbs is one . Because only one box has 8 to 10 defective bulbs.
• To find the mean of defective bulbs:

            $Sol. \\Interval\\0-2\\2-4\\4-6\\6-8\\8-10$               $x_{i}\\\\\frac{2+0}{2}=1 \\\frac{2+4}{2}=3\\\frac{6+8}{2}=5\\\frac{6+8}{2}=7\\\frac{8+10}{2}=9$           $f_{i}\\\\3\\4\\5\\3\\1$            $f_{i}x_{i}\\\\3\\12\\25\\21\\9$

         From the above table:  $\sum f_{i}=16$  and $\sum f_{i} x_{i}=70$

         Mean $=\frac{\sum f_{i}x_{i}}{\sum f_{i}}$

         Mean $=\frac{70}{16}=4.375Bulbs$

• Probability to get box with 2 to 4 bulbs are defective $=\frac{4}{16}=\frac{1}{4}$
• Only one box contains highest number of defective bulbs.

    Probability of getting box with highest number of defective bulbs $=\frac{1}{16}$