Answer:
(-5,-4)
Step-by-step explanation:
Given:
Cards labelled 1, 3, 5, 6, 8 and 9.
A card is drawn and not replaced. Then a second card is drawn at random.
To find:
The probability of drawing 2 even numbers.
Solution:
We have,
Even number cards = 6, 8
Odd numbers cards = 1, 3, 5, 9
Total cards = 1, 3, 5, 6, 8 and 9
Number of even cards = 2
Number of total cards = 6
So, the probability of getting an even card in first draw is:



Now,
Number of remaining even cards = 1
Number of remaining cards = 5
So, the probability of getting an even card in second draw is:


The probability of drawing 2 even numbers is:



Therefore, the probability of drawing 2 even numbers is
. Hence, the correct option is (b).
This question is gonna need the picture to go with it
Answer:
A) 68.33%
B) (234, 298)
Step-by-step explanation:
We have that the mean is 266 days (m) and the standard deviation is 16 days (sd), so we are asked:
A. P (250 x < 282)
P ((x1 - m) / sd < x < (x2 - m) / sd)
P ((250 - 266) / 16 < x < (282 - 266) / 16)
P (- 1 < z < 1)
P (z < 1) - P (-1 < z)
If we look in the normal distribution table we have to:
P (-1 < z) = 0.1587
P (z < 1) = 0.8413
replacing
0.8413 - 0.1587 = 0.6833
The percentage of pregnancies last between 250 and 282 days is 68.33%
B. We apply the experimental formula of 68-95-99.7
For middle 95% it is:
(m - 2 * sd, m + 2 * sd)
Thus,
m - 2 * sd <x <m + 2 * sd
we replace
266 - 2 * 16 <x <266 + 2 * 16
234 <x <298
That is, the interval would be (234, 298)