Answer:
x > 4
Step-by-step explanation:
3x - 7 > 5
3x - 7 + 7 > 5 + 7
3x > 12
x > 4
Answer:
6
Step-by-step explanation:
Complete Question
A set of magical wand prices are normally distributed with a mean of 50 dollars and a standard deviation of 4 dollars. A blackthorn wand has a price of 45.20. What proportion of wand prices are lower than the price of the blackthorn wand? You may round your answer to four decimal places
Answer:
0.1151
Step-by-step explanation:
We solve using z score formula
z = (x-μ)/σ, where
x is the raw score = $45.20
μ is the population mean = $50
σ is the population standard deviation = $4
We are solving for x < 45.20
Hence:
z = 45.20 - 50/4
z = -1.2
Probability value from Z-Table:
P(x<45.20) = 0.11507
Approximately to 4 decimal places = 0.1151
Therefore, the proportion of wand prices that are lower than the price of the blackthorn wand is 0.1151
P(A) = P(8) + P(9) + P(10) = 3/10 so P(A complement) = 1 - P(A) = 1 - 3/10 = 7/10 - D
