Answer:
c
Step-by-step explanation:
Answer:
(1/2)s = 345
s = 690 (Maggie's savings balance)
Step-by-step explanation:
For any problem, word problem or otherwise, you start be reading and understanding the problem. You should specifically look for
- what you're being asked to find (what is the question to answer)
- the information you're given that is relevant to the question asked.
Here, you're asked to find a savings account balance. You're told that $345 is half that amount.
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After you decide what you're looking for and the given relevant information, you use the problem statement and your personal knowledge to write one or more equations relating what you know to what you want to find.
A first step for doing this is to define any necessary variables. In this problem, we can use "s" for the original savings balance (in dollars). (I like to choose letters that remind me what they stand for. "x" or "y" can sometimes get mixed up. For a one-variable problem, it doesn't really matter what you call it. It is helpful to be clear about the units of measure of any variables. Confusion there can also lead to errors.)
The problem statement tells us that half the savings account amount is $345, so our equation is ...
(1/2)s = 345
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The "one step" required to solve this so to multiply both sides of the equation by 2.
s = 690
Maggie had $690 in her savings account before she bought the computer.
For a standard normal distribution, the expression that is always equal to 1 is P(z≤-a)+P(-a≤z≤a)+P(Z≥a). This expression represents all of the possible values in a curve, or in other words, the total area of a curve. According to standard normal distribution, the total area of a curve is always equal to 1.
The answer to this is 500 my friend. 10 times 10 equals 100. 100 times 5 equals 500. hope this helps:)
Answer:
P ( -1 < Z < 1 ) = 68%
Step-by-step explanation:
Given:-
- The given parameters for standardized test scores that follows normal distribution have mean (u) and standard deviation (s.d) :
u = 67.2
s.d = 4.6
- The random variable (X) that denotes standardized test scores following normal distribution:
X~ N ( 67.2 , 4.6^2 )
Find:-
What percent of the data fell between 62.6 and 71.8?
Solution:-
- We will first compute the Z-value for the given points 62.6 and 71.8:
P ( 62.6 < X < 71.8 )
P ( (62.6 - 67.2) / 4.6 < Z < (71.8 - 67.2) / 4.6 )
P ( -1 < Z < 1 )
- Using the The Empirical Rule or 68-95-99.7%. We need to find the percent of data that lies within 1 standard about mean value:
P ( -1 < Z < 1 ) = 68%
P ( -2 < Z < 2 ) = 95%
P ( -3 < Z < 3 ) = 99.7%
