The percentage of young adults send between 128 and 158 text messages per day is; 34%
<h3>How to find the percentage from z-score?</h3>
The distribution is approximately Normal, with a mean of 128 messages and a standard deviation of 30 messages.
We are given;
Sample mean; x' = 158
Population mean; μ = 128
standard deviation; σ = 30
We want to find the area under the curve from x = 248 to x = 158.
where x is the number of text messages sent per day.
To find P(158 < x < 248), we will convert the score x = 158 to its corresponding z score as;
z = (x - μ)/σ
z = (158 - 128)/30
z = 30/30
z = 1
This tells us that the score x = 158 is exactly one standard deviation above the mean μ = 128.
From online p-value from z-score calculator, we have;
P-value = 0.34134 = 34%
Approximately 34% of the the population sends between 128 and 158 text messages per day.
Read more about p-value from z-score at; brainly.com/question/25638875
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1.348e+16 joules
2.7x10 17 joules
Answer:
14 boys
Step-by-step explanation:
Let us try to formulate the expressions one by one.
let the number be x.
Step 1:
six time the number is 6*x = 6x
Step 2:
product of the number and -3 is -3x
Step 3:
now let us make equation for it:
adding 3x on the left side,
dividing right side by 9
x=45/9 = 5
So the number is x=5
Answer:
x = 5.25
Step-by-step explanation:
width = x
length = (x + 8)
length that overlaps with width = (x + 8) - x = 8
perimeter (clockwise)
= 90
= x + 8 + (x + 8) + x + (x + 8) + x + 8 + (x + 8) + x + (x + 8)
= 8x + 6(8)
= 8x + 48
8x + 48 = 90
8x = 42
x = 5.25
