4. D
12/15 isn't the same as 30/40. 12/15=0.8, while 30/40=0.75. All the other options are equal.
5. C
Of course, you could figure this out by plugging in all the answers, and seeing which ones make the two sides equal, however, cross multiplying (multiplying the top of one fraction with the bottom of the other fraction) would be much faster. This will be your equation: 8*46=18*n. After combining like terms and dividing, you should find that n=20.
6. A
This problem is basically the same as #5. Cross multiplying so the equation you get will be 0.6*1.2=1.6*w. W should be 0.45.
Hope this helps!!
Divide 30 by 3 and you get 10. Divide 30 by 2 and your get 15. Add 15 to 10 and you get 25. 25 is your answer.
16% would be the correct answer
Answer:
A binomial probability density function should be used because the question asks for determining the probability that exactly 10 students wear glasses.
Step-by-step explanation:
A binomial probability density function is used when we want to know the probability of an exact value.
A cumulative distribution function is used when we want to know the probability of less than or equal to a value.
