Answer:
a) 615
b) 715
c) 344
Step-by-step explanation:
According to the Question,
- Given that, A study conducted by the Center for Population Economics at the University of Chicago studied the birth weights of 732 babies born in New York. The mean weight was 3311 grams with a standard deviation of 860 grams
- Since the distribution is approximately bell-shaped, we can use the normal distribution and calculate the Z scores for each scenario.
Z = (x - mean)/standard deviation
Now,
For x = 4171, Z = (4171 - 3311)/860 = 1
- P(Z < 1) using Z table for areas for the standard normal distribution, you will get 0.8413.
Next, multiply that by the sample size of 732.
- Therefore 732(0.8413) = 615.8316, so approximately 615 will weigh less than 4171
- For part b, use the same method except x is now 1591.
Z = (1581 - 3311)/860 = -2
- P(Z > -2) , using the Z table is 1 - 0.0228 = 0.9772 . Now 732(0.9772) = 715.3104, so approximately 715 will weigh more than 1591.
- For part c, we now need to get two Z scores, one for 3311 and another for 5031.
Z1 = (3311 - 3311)/860 = 0
Z2 = (5031 - 3311)/860= 2
P(0 ≤ Z ≤ 2) = 0.9772 - 0.5000 = 0.4772
approximately 47% fall between 0 and 1 standard deviation, so take 0.47 times 732 ⇒ 732×0.47 = 344.
60
D>0, there are 2 distinct real roots
Explanation:
3x2+6x−2=0
a=3,b=6,c=−2
The formula for discriminant is b2−4acSubstitute the given values.
b2−4ac
(6)2−4(3)(−2)
=60
therefore, D>0, there are 2 distinct real roots
Answer:
Una linea di adattamento ottimale è una linea retta che rappresenta al meglio i dati su un diagramma a dispersione. Questa linea può passare attraverso alcuni dei punti, nessuno dei punti o tutti i punti
Step-by-step explanation:
Answer:
X=-8
Step-by-step explanation:
3x-4=7×-4
3x-4=-28
3x=-28+4
3x=-24
x=-24/3
x=-8
