Guppies: u
Goldfish: o
3 times as many guppies as goldfish
3*o = u (there are more guppies than goldfish)
o + u = 20
o = 20 - u
Substitute in (20 - u) for o in the first equation and solve:
3* (20 - u) = u
60 - 3u = u
60 = 4u
u = 15
He has 15 guppies. Then substitute in the number of guppies into either equation to find the number of goldfish:
o + u = 20
o + (15) = 20
o = 5
Hope this helps! :)
Yes it is true that commercial truck owners violate laws requiring front license plates at a higher rate than owners of passenger cars because null hypothesis is rejected.
Given among 2049 Connecticut passenger cars, 239 had only rear license plates. Among 334 Connecticut trucks, 45 had only rear license plates.
let
be the probability that commercial cars have rear license plates and
be the probability that connected trucks have rear license plates.
Cars Trucks Total
Total 2049 334 2383
x 239 45 284
p 0.1166 0.1347 0.1191
α=0.05
Hypothesis will be :


It is a left tailed test at 0.05 significance.
Standard errors of p=
=
=
=0.0066
Test statistic Z=p difference/standard error
=(0.1166-0.1347)/0.0066
=-0.0181/0.0061
=-2.967
p value=0.001505<5%
Since p is less than 5% we reject null hypothesis.
We cannot calculate standard deviation so we cannot calculate confidence interval.
Hence there is statistical evidence at 5% significance level to support that commercial truck owners violate laws requiring front license plates at a higher rate than owners of passenger cars.
Learn more about z test at brainly.com/question/14453510
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Answer:
17.5, divide 70 by 4
Step-by-step explanation:
what i said above
18% of 40 is 7.2
Change the percentage (18%) into a decimal by dividing it over 100:
18/100 = 0.18
Divide 7.2 by the decimal (0.18):
7.2 / 0.18 = 40