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hello everyone please I need help with this question quickly!
The table shows some information about the lifetimes, t, in hours, of some lightbulbs.

Lifetime Frequency
25 < t ≤ 50 100
50 < t ≤ 100 45
100 < t ≤ 150 67
150 < t ≤ 200 50
200 < t ≤ 250 0
250 < t ≤ 300 12
300 < t ≤ 350 16

Estimate the mean lifetime of a bulb.
Give your answer rounded to 2 DP.

Respuesta :

fieryanswererft

Answer:

112.93

Explanation:

[tex]\sf \boxed{\sf Mean= \frac{interval \ midpoint \ x \ frequency }{Total \ Frequency} }[/tex]

Solving Stepwise:

[tex]\rightarrow \sf \dfrac{37.5 \ x \ 100 \ + \ 75 \ x \ 45 \ + \ 125 \ x \ 67 \ + \ 175 \ x \ 50 \ + \ 225 \ x \ 0 \ + \ 275 \ x \ 12 \ + \ 325 \ x \ 16 }{100 + 45 +67+50+0+12+16}[/tex]

[tex]\rightarrow \sf \dfrac{32750}{290}[/tex]

[tex]\rightarrow \sf \dfrac{3275}{29}[/tex]

[tex]\rightarrow \sf 112.9310345[/tex]

[tex]\rightarrow \sf 112.93 \ (rounded \ to \ nearest \ 2 \ decimal \ places)[/tex]