Answer:8
Step-by-step explanation: you need to have the variable c all by itself. Since the 4 is being divided by c you need to multiply 4 on both sides. Making it 4*2=c. Therefore c=8
Answer:

Step-by-step explanation:
Average life of electric bulbs = 300 hrs
standard deviation = 45
Total no of bulbs tested = 100
Probability that sample mean is less than 295 =?
Using Central Limit Theorem

From table of normal distribution:
