Answer:
Step-by-step explanation:
Hello!
X: Cholesterol level of a woman aged 30-39. (mg/dl)
This variable has an approximately normal distribution with mean μ= 190.14 mg/dl
1. You need to find the corresponding Z-value that corresponds to the top 9.3% of the distribution, i.e. is the value of the standard normal distribution that has above it 0.093 of the distribution and below it is 0.907, symbolically:
P(Z≥z₀)= 0.093
-*or*-
P(Z≤z₀)= 0.907
Since the Z-table shows accumulative probabilities P(Z<Z₁₋α) I'll work with the second expression:
P(Z≤z₀)= 0.907
Now all you have to do is look for the given probability in the body of the table and reach the margins to obtain the corresponding Z value. The first column gives you the integer and first decimal value and the first row gives you the second decimal value:
z₀= 1.323
2.
Using the Z value from 1., the mean Cholesterol level (μ= 190.14 mg/dl) and the Medical guideline that indicates that 9.3% of the women have levels above 240 mg/dl you can clear the standard deviation of the distribution from the Z-formula:
Z= (X- μ)/δ ~N(0;1)
Z= (X- μ)/δ
Z*δ= X- μ
δ=(X- μ)/Z
δ=(240-190.14)/1.323
δ= 37.687 ≅ 37.7 mg/dl
I hope it helps!
Answer:
75%
Step-by-step explanation:
there is a 75% chance of getting a red marble as there is 15/20 marbles that are red
Answer: 1/8
Step-by-step explanation:
Hypotenuse = √97
One leg = 4
By Pythagoras theorem, second leg² = (√97)² - 4²
= 97 - 16 = 81
So second leg = 9
Area of triangle = 4 x 9 / 2 = 18 sq inch
One sq foot = 144 sq inch
So required fraction = 18/144 = 1/8
A graph shows the vertex to be at (1.5, 4.75).
The equation of the axis of symmetry is x=1.5.
_____
If you want to find it analytically, you can put the equation in standard form.
y = -3(x -2)² +4 -(3x -6)
y = -3x^2 +9x -2
This is of the form y = ax² +bx +c with a=-3 and b=9. The axis of symmetry is given by ...
x = -b/(2a) = -9/(2×(-3)) = 3/2 . . . . . same as above
