X = 4
First take 12x off both sides, so -7x=-28
The negatives cancel out, so 7x=28
Not find the hcf and divide by that.
Answer: 2.14 %
Step-by-step explanation:
Given : pH measurements of a chemical solutions have
Mean : 
Standard deviation : 
Let X be the pH reading of a randomly selected customer chemical solution.
We assume pH measurements of this solution have a nearly symmetric/bell-curve distribution (i.e. normal distribution).
The z-score for the normal distribution is given by :-

For x = 6.74

For x = 6.76

The p-value =

In percent, 
Hence, the percent of pH measurements reading below 6.74 OR above 6.76 = 2.14%
Answer:
0.68
Step-by-step explanation:
Given that :
P(trombone | snow) = 0.8 ;
P(trombone | no snow) = 0.5
P(snow) = 0.6
P(trombone) = P(trombone | snow) * p(snow) + P(trombone | no snow) * p(no snow)
P(no snow) = 1 - 0.6 = 0.4
Hence,
P(trombone) = P(trombone | snow) * p(snow) + P(trombone | no snow) * p(no snow)
P(trombone) = (0.8 * 0.6) + (0.5 * 0.4)
P(trombone) = 0.48 + 0.20
P(trombone) = 0.68
Answer: D $852.00
Step-by-step explanation: