Answer:
191
Step-by-step explanation:
Sorry it's sideways. I drew a box chart for this. First, fill in what you know: the number of white and black beads Ally has. Then, calculate how many black beads Betty has (Ally's number, 59, minus 35.) 59-35 = 24.
They tell you the total number of beads is 346. Add up Ally's total to get 131, then subtract that from 346. That's Betty's total beads, 215.
Last, subtract the 24 black beads Betty has from the 215 total to get 191.
Answer:
The third option (9+-
-
)
Step-by-step explanation:
With FOIL, this can be expanded. (a+b)(a-b) is equal to a²+ab-ab-b² or a²-b².
In this case, all the answers have 4 terms, so we want the first option. This makes the equation 3²+(3×)-(3×
)-(
)².
Solving these gives 9+-
-7. This is the same as 9+
-
-
.
**This content involves multiplying with surds and expanding perfect squares, which you may wish to revise. I'm always happy to help!
Answer:
a) Standard Deviation = 2.74
b) Significantly Low = values below 24.52 (or equal)
Significantly High = values above 35.48 (or equal)
Step-by-step explanation:
This is binomial probability distribution problem.
Where n = 40 [groups of 40, total trials]
p = 0.75 [probability of success]
a)
The formula for standard deviation is:
We know n = 40 and p = 0.75, so the standard deviation is:
b)
the range rule of thumb tells us that usual range of values is within 2 standard deviation of the mean. First let's calculate mean.
We know,
Mean = n * p = 40 * 0.75 = 30
So
Mean - 2* Standard Deviation = 30 - 2(2.74) = 24.52
and
Mean + 2* Standard Deviation = 30 + 2(2.74) = 35.48
Significantly Low = values below 24.52 (or equal)
Significantly High = values above 35.48 (or equal)