Answer:
0.3520
Step-by-step explanation:
We have been given that the pulse rates among healthy adults are normally distributed with a mean of 80 beats/second and a standard deviation of 8 beats/second. We are asked to find the proportion of healthy adults have pulse rates that are more than 83 beats/sec.
First of all, we will find z-score corresponding to sample score of 83 as:
, where,
z = Z-score,
x = Sample score,
= Mean,
= Standard deviation.
Upon substituting our given values in z-score formula, we will get:

Now, we need to find the probability that a z-score is greater than 0.38.
Using formula
, we will get:

Using normal distribution table, we will get:



Therefore, 0.3520 of healthy adults have pulse rates that are more than 83 beats/sec.
Answer : x=-2,y=4.
The second equation is multiplied by 5 and give it equation (3) and then subtract the first and third equations .You’ll first get the value ‘y’ and then substitute the value of ‘y’ in the first equation.Finally you’ll get the value of ‘x’.
Answer:
76
Step-by-step explanation:
4^2 x 5^2 - 18^2
PEMDAS is our acronym for order of operations: Parentheses, exponents, multiplication, division, addition, subtraction.
Since we have no parentheses, we'll calculate the numbers and exponents (PEMDAS) first. "to the power of 2" is also called "squared" and means multiplying that number by itself.
(4x4) x (5x5) - (18x 18)
=16 x 25 - 324
Now we multiply: (PEMDAS)
= 400 - 324
then subtract: (PEMDAS)
=76