12.6^2 - 0^2 / 2 x 16
= <u>4.961</u><u>2</u><u>5</u>
Hope this helped uyou-Have a good day bro cya)
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
Answer:
X= 5, -9
Step-by-step explanation:
(X+2)² =49
Expand the bracket,
(X+2) (X+2)= 49
Apply the distributive property;
X(X+2) +2 (X+2) =49
X²+2X+2X+4=49
X²+4X+4=49
Move 49 to the left side of the equation;
X²+4X+4-49=0
X²+4X-45=0
Apply Factorisation method;
Consider the form
a²+bx+c=0
Find two numbers whose sum is equal to b and whose product is equal to c.
Comparing with our equation;
B =4 and C =45
We can use 9 and -5, this is because ;
9+(-5)=4 and 9*(-5)= 45.
Replace X +4X-45=0 with (X-5) (X+9)=0
Therefore;
X-5=0
X+9=0
Moving to the left side of the equation;
Therefore X= 5 and -9
Answer:
Step 2
Step-by-step explanation:
In step 2 the expression was 40+20 which would have been 60 but he might have thought addition sign was subtraction so he did 40-20 which is 20 so he is wrong made mistake in step 2