11. You’ve done it correctly
12. Let x^2=y
y^2+13y+40=0
(y+8)(y+5)=0
y=8, 5
Since y=x^2
x^2=8 x^2=5
x=+/-√5 x= +/-2√2
13. x^4-x^2-x^2-8=0
x^4-2x^2-8=0
let x^2=y
Y^2-2y-8=0
(y-4)(y+2)=0
y=4, -2
Since y=x^2
X^2=4 X^2=-2
X= +/- 2 This wouldn’t be a real solution
14. It’s pretty much the same process, just substitute y in for x^2. If you’re confused feel free to ask and I can do it, or you can put it through Photomath
15. You’re on the right track so I’m just going to continue from where you left off
x^2(4x+5)-4(x+5)=0
(x^2-4)(4x+5)=0
x= +/- 2 4x=5
x=5/4 or 1 1/4
Hope this helped :)
-1.43*0.11= -0.1573
That should be it
We are asked to find the probability that a data value in a normal distribution is between a z-score of -1.32 and a z-score of -0.34.
The probability of a data score between two z-scores is given by formula
.
Using above formula, we will get:

Now we will use normal distribution table to find probability corresponding to both z-scores as:


Now we will convert
into percentage as:

Upon rounding to nearest tenth of percent, we will get:

Therefore, our required probability is 27.4% and option C is the correct choice.
The answer to this question is A). 39 b). 56
The integer you’re looking for is 3