Answer:
Step-by-step explanation:
a) 3x^2-12x-11=3*x^2-3*2*2*x+3*4-23=3*(x^2-2*2x+2^2)-23=3*(x-2)^2-23
so a= -2 ,b= -23
b) x1=[12+V(12^2-4*3* -11)]/6=12/6+V(144+132)/6=2+2/6V69=2+1/3V69=
2+V69/9=2+V23/3
c=2, d= 23/3
Answer:
96
Step-by-step explanation:
<u>Step 1
</u>
Divide your confidence interval by 2. In this case the confidence is 95% = 0.095, so 0.095/2 = 0.0475
<u>Step 2
</u>
Use either a z-score table or a computer to find the closest z-score for 0.0475 and you will find this value is 1.96
<u>Step 3
</u>
Divide the margin error by 2. In this case, the margin error is 2%. When dividing this figure by 2, we get 1% = 0.01
<u>Step 4
</u>
Divide the number obtained in Step 2 by the number obtained in Step 3 and square it
1.96/0.01 = 196 and 196 squared is 38,416
<u>Step 5
</u>
As we do not now a proportion of people that purchase on line, we must assume this value is 50% = 0.5. Square this number and you get 0.25
<u>Step 6
</u>
Multiply the number obtained in Step 5 by the number obtained in Step 4, round it to the nearest integer and this is an appropriate size of the sample.
38,416*0.25 = 9,604
Answer:
1.56
Step-by-step explanation:
Don't forget your decimal placement. other than that you are correct I believe
Answer:
im black
Step-by-step explanation:
mary + mom = 36
mom = 5x mary
mary + 5mary = 36
6 mary = 36
mary = 36/6 =6
mary is 6 years old
her mother is 5 x 6 = 30 years old
