Answer: d
Step-by-step explanation:
The probability of not being purple is the probability of the three other colors. Suppose the number of purple marbles is x. Then we have 20+30+40+x = 90 + x marbles. Then the probability of not being purple is 90/(90+x). If this fraction can have a lowest term for some value of x, then the numerator of this lowest term must be a factor of 90.
Checking through the options, only option D has a non-factor of 90 as its numerator.
Answer:
a) The confidence interval is
.
Step-by-step explanation:
We have to calculate a confidence interval (CI) of a difference of proportions.
For the existing procedure, the proportion is:

For the new procedure, the proportion is:

To calculate the CI, we need to estimate the standard deviation

For a 90% CI, the z-value is 1.64.
Then, the CI is:

Answer:
Equilateral Triangle
Step-by-step explanation:
Since each side is the same length, divide the perimeter by side length to get the number of sides.
36in ÷ 12in = 3
A triangle has 3 sides.
Area = base * altitude = 2 * 2.9 = 5.8 cm^2
Answer:
akjnajknlkicea
Step-by-step explanation: