Answer:
The average speed of car is 67 kilometers per hour.
Step-by-step explanation:
Given that:
Distance travelled in one hour = 45 km
Distance travelled in next 2 hours = 78*2 = 156 km
Total distance = 45+156 = 201
Total time = 1+2 = 3 hours
Average speed of the car = 
Average speed of the car = 
Average speed of the car = 67 km/hr
Hence,
The average speed of car is 67 kilometers per hour.
Answer:
40
Step-by-step explanation:
(252-12)/6=40
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
=
= 
95% of all values lie within the 2 standard deviation from mean
=
= 
99.7% of all values lie within the 3 standard deviation from mean
=
= 
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%
(9x+5) - (6x-8) = 9x+5 - 6x+8 = (9x-6x) + (5+8) = 3x+13
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(4x+10) - (-3x+5) = 4x+10 + 3x-5 = (4x+3x) + (10-5) = 7x+5