Answer:
50%
Step-by-step explanation:
68-95-99.7 rule
68% of all values lie within the 1 standard deviation from mean 
95% of all values lie within the 1 standard deviation from mean 
99.7% of all values lie within the 1 standard deviation from mean 
The distribution of the number of daily requests is bell-shaped and has a mean of 55 and a standard deviation of 4.

68% of all values lie within the 1 standard deviation from mean
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95% of all values lie within the 2 standard deviation from mean
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99.7% of all values lie within the 3 standard deviation from mean
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Refer the attached figure
P(43<x<55)=2.5%+13.5%+34%=50%
Hence The approximate percentage of light bulb replacement requests numbering between 43 and 55 is 50%
Latoya would need 32 cups of juice to make 2 gallons.