Answer:
Option D. 938/969
Step-by-step explanation:
At most 2 defective means 2 or less than 2 bulbs are defective
So, we have 3 cases:
a) No defective bulb. b) 1 defective bulb. c) 2 defective bulbs
Case a) No defective bulb
Total number of bulbs = 20
Number of defective bulbs = 5
Number of non-defective bulbs = 15
Total number of ways to select 0 defective bulb = 15C4 = 1365
Case b) 1 defective bulb
Total number of ways to select 1 defective bulb = 15C3 x 5C1 = 2275
Case c) 2 defective bulbs
Total number of ways to select 2 defective bulbs = 15C2 x 5C2 = 1050
Therefore, total number of ways to select at most 2 defective bulbs = 1365 + 2275 + 1050 = 4690
Total number of ways to select 4 bulbs from 20 = 20C4 = 4845
Therefore, probability of selecting at most 2 defective bulbs =
Therefore, option D gives the correct answer.
Answer:
Option: D is correct.
Step-by-step explanation:
since we are given a inequality as:
Clearly from the graph of the following inequality we could see that the origin is included in the shaded region and the shaded area is below the line.
Also it could be seen that if we put the origin points i.e. (0,0) in the inequality than 0<2 and the condition is true and hence origin is included in the shaded area.
Hence, option D is true.
Answer:
The probability that it would take more than four hours to construct a soapbox derby car = 0.1587 or 15.87
Step-by-step explanation:
Given -
Mean = 3 hours
Standard deviation = 1 hours
Let X be the no of hours to construct a soapbox derby car
the probability that it would take more than four hours to construct a soapbox derby car =
=
= Put
= 1 -
= 1 - .8413 Using z table
= 0.1587