Answer:
Billy is a fly enthusiast! He has a huge glass container filled with 506 flies! One day when Billy went to feed the flies, he accidentally left the screw opened for too long, and 8 flies escaped! How many flies are left in the tank?
Answer:
B. Stratified sampling, because there are specific subgroups to investigate.
Step-by-step explanation:
Stratified Sampling is a sampling method and is used when the population has subgroups with different characteristics. Random sampling is applied in each of the sub-groups <em>proportional </em>to their size and then these samples <em>combined </em>together to create sample of the study.
Since there are three towns with people from different occupations ( retirees,business owners, office workers), it is better to use stratified sampling method.
For the second one 1 mph equals 1.6 km so i’m pretty sure it would be all of them
Answer:
C
Step-by-step explanation:
A. is wrong because having a different height for each seedling and not trying to keep it equal is simply worse than making sure the heights are identical.
B. Completely wrong because it would likely result in 1 plot having more melon seedlings than the other.
C. Correct because it makes sure the seedlings are the same height at the beginning of the experiment, allowing less randomness in the experiment.
D. Putting the taller of a each pair for 1 plot makes it the experiment rigged in favor of the plot with taller seedlings
E. Same issue as D.
The distribution of X is X ~ N (20 , 6) and the probability that this American will receive no more than 24 Christmas cards this year is 0.7486.
<h3>Probability</h3>
a. Distribution
X ~ N (20 , 6)
b. P(x ≤24)
= P[(x - μ ) / σ (24 - 20) / 6]
= P(z ≤0.67)
= 0.74857
=0.7486
Hence:
Probability = 0.7486
c. P(21 < x < 26)
= P[(21 - 26)/ 6) < (x - μ ) / σ < (24 - 20) / 6) ]
= P(-0.83 < z < 0.67)
= P(z < 0.67) - P(z < -0.)
= 0.74857- 0.2033
= 0.54527
Hence:
Probability =0.54527
d. Using standard normal table ,
P(Z < z) = 66%
P(Z < 0.50) = 0.66
z = 0.50
Using z-score formula,
x = z× σ + μ
x = 0.50 × 6 + 20 = 23
23 Christmas cards
Therefore the distribution of X is X ~ N (20 , 6) and the probability that this American will receive no more than 24 Christmas cards this year is 0.7486.
Learn more about probability here:brainly.com/question/24756209
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