Answer – C. the sample size 16 is too small
If we toss a coin 16 times in order to test the hypothesis
H0: p = 0.5 that the coin is balanced, we can't use the z-test for a proportion
in the situations because the sample size 16 is too small. The z-test is best
used when the sample size is greater than 30; when the sample size is less than
30, t-test is more appropriate.
A full circle = 360 degrees.
The sum of the shaded portions is : 60 + 55 + 45 = 160.
The probability would be the shaded portion divided by the full circle:
160 / 360 = 0.44
The expected completion time is μ = 40 weeks.
The random variable, X = 38 weeks (the probable time)
If the standard deviation is σ, then the z-score is z = (x - μ)/σ.
Let us test the given standard deviations.
When σ=1,
z = (38-40)/1 = -2
From standard tables,
P(x<=38) = P(z<=-2) = 0.0228 =2.3%
When σ=2,
z = (38*40)/2 = -1
P(x<=38) = P(z<=-1) = 0.1587 = 15.9%
When σ=4,
z = (38-40)/4 = -0.5
P(x<=38) = P(z<=-0.5) = 0.3085 = 30.9%
Answers:
z=1 => 2.3%
z=2 => 16% (approx)
z=4 => 31% (approx)
Answer:
3
Step-by-step explanation:
To evaluate the expression, we have to substitute the variable in the expression, z, for its stated value. Given that z = 6, substitute 6 for the z in the expression and solve:
Thus, the answer is 3.
