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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
Answer:
But over here in delaware is 32
Answer:
4
Step-by-step explanation:
Add each sample separately
A.17 B. 47 C. 39 D. 52 E. 45
Then you add them all together which totals 200 sick days
We know that they surveyed 5 schools and 10 students at random from each one. So we want to know the mean of sick days the students took not the schools in all.
So we divide 200/50
And get a mean of 4.
So each student took an average of 4 sick days each in the country.
(2x - 1)(6x - 7)
2x(6x - 7) - 1(6x - 7)
2x(6x) - 2x(7) - 1(6x) + 1(7)
12x² - 14x - 6x + 7
12x² - 20x + 7