Well the sum is 15+6=21. then you must do 81-21=60. So your answer must be t=60.
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Complete Question
Researchers recorded the speed of ants on trails in their natural environments. The ants studied, Leptogenys processionalis, all have the same body size in their adult phase, which made it easy to measure speeds in units of body lengths per second (bl/s). The researchers found that, when traffic is light and not congested, ant speeds vary roughly Normally, with mean 6.20 bl/s and standard deviation 1.58 bl/s. (a) What is the probability that an ant's speed in light traffic is faster than 5 bl/s? You may find Table B useful. (Enter your answer rounded to four decimal places.)
Answer:
0.7762
Step-by-step explanation:
We solve using z score formula
z = (x-μ)/σ, where
x is the raw score
μ is the population mean
σ is the population standard deviation.
Population mean = 6.20 bl/s
Standard deviation = 1.58 bl/s.
x = 5 bl/s
z = 5 - 6.20/1.58
z = -0.75949
The probability that an ant's speed in light traffic is faster than 5 bl/s is P( x > 5)
Probability value from Z-Table:
P(x<5) = 0.22378
P(x>5) = 1 - P(x<5)
= 1 - 22378
= 0.77622
Approximately to 4 decimal places = 0.7762
The probability that an ant's speed in light traffic is faster than 5 bl/s is 0.7762
Answer:
Reject the null hypothesis.
Step-by-step explanation:
n1 = 16
n2 = 21
S.V1 = 5.8
S.V2 = 2.4
= 0.05
= Population Variance 1 ≤ Population Variance 2
= Population Variance 1 > Population Variance 2
Test statistic value = 5.8 / 2.4 = 2.417
Degrees of freedom is n - 1
15 and 20
Critical value is
= 2.2
2.417 > 2.2
we reject the null hypothesis as the critical value is greater than the test statistic.
17. Area of triangle: 1/2bh
1/2 * 12 * 15
1/2 * 180
=90 cm^2
18. Area of trapezoid: 1/2 h (b1 + b2)
1/2 * 8 ( 12 + 15.4)
4 * 27.4
= 109.6 cm^2
The difference (faculty-student) in the sample proportions of those who believe that five minutes is not enough time for students to change classes typically varies about 0.096 from the true difference in proportions. Option D is correct.
<h3>What is the standard deviation?</h3>
It is a measurement of statistical data dispersion. The degree to which the value varies is known as standard deviation.
The standard deviation of the sampling distribution is found as;

The difference in the sample proportions of those who think five minutes is not enough time for students to switch classrooms generally differs by roughly 0.096 from the actual difference in proportions.
Hence option D is correct.
To learn more about the standard deviation, refer to: brainly.com/question/16555520.
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