(a-25b)(a+4b)=0
Use the quadratic formula or complete the square by looking at the factors
Answer:
2.5% of IQ scores are no more than 65
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 95
Standard deviation = 15
Using the empirical rule, what percentage of IQ scores are no more than 65?
65 = 95 - 2*15
So 65 is two standard deviations below the mean.
By the Empirical Rule, 95% of the measures are within 2 standard deviation of the mean. Of those 5% which are not, 2.5% are more than 2 standard deviations above the mean and 2.5% are more than 2 standard deviations below the mean.
So 2.5% of IQ scores are no more than 65
60 is the common multiple
If you draw a diagram of this, your given values of the resulting triangle give you the sides opposite and adjacent of the angle. The formula that uses these sides is tangent.
The tangent of an angle is equal to the ratio of the opposite side over the other non-hypotenuse side (adjacent).
Therefore;
Where x is the length of the string in feet.