Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:
Where
and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard table or excel and we got:
Answer:
(c) micrograms (µg)
Step-by-step explanation:
Answer:
x = 48
Step-by-step explanation:
3x + 9 = 153
subtract 9 from both sides -9 -9
3x = 144
divide both sides by 3 3x/3 = 144/3
2x + (x + 9) = 153
2(48) + (48 + 9) = 153
96 + 57 = 153
153 = 153
Answer:
20
Step-by-step explanation:
Step 1: 4 = 20% × Y
Step 2: 4 = 20/100 × Y
Multiplying both sides by 100 and dividing both sides of the equation by 20 we will arrive at:
Step 3: Y = 4 × 100/20
Step 4:Y = 4 × 100 ÷ 20
Step 5: Y = 20
One integer is m.
The other integer is n.
n = 23m + 5
mn = 6732
m = 6732/n
n = 23 * 6732/n + 5
n = 154,836/n + 5
n^2 = 154,836 + 5n
n^2 - 5n - 154,836 = 0
n = [5 +- sqrt(25 + 4 * 154,836)]/2
n = (5 +- 787)/2
n = 396 or n = -391
We discard -391 because the problem is looking for positive integers.
mn = 6732
m = 6732/n = 6732/396
m = 17
Answer: The integers are 17 and 396.