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Answer:
C. 18 inches
Step-by-step explanation:
The median of a trapezoid is the line segment that joins the midpoints of the sides of the trapezoid. It is halfway between the parallel bases, and is parallel to them. It length is the average of the lengths of the two bases:
(15 +21)/2 = 36/2 = 18 . . . . inches
A null hypothesis (H₀) can be defined the opposite of an alternate hypothesis (H₁) and it asserts that two (2) possibilities are the same.
For the baker's claim, the appropriate null and alternative hypotheses would be given by:
H₀: μ ≤ 15
H₁: μ > 15
Since the standard deviation for the height is given, the population would have a normal distribution, and the population standard deviation is given by:
Population standard deviation = σ/√n
Population standard deviation = 0.5/√10
Population standard deviation = 0.16.
For the p-value, we have:
The p-value is the probability that a sample mean would be the same or greater than (≥) 17 cm. Thus, the p-value is given by:
p-value = P(x > 17) ≈ 0.
Since the p-value is approximately equal to zero (0), we can conclude that there is sufficient evidence that the true mean height for the baker's loaves of bread is greater than (>) 15 cm.
Question 3.
For the oil company's claim, the appropriate null and alternative hypotheses would be given by:
H₀: μ = 0.15
H₁: μ > 0.15
<h3>How to calculate value of the z-score?</h3>The z-score can be calculated by using this formula:
<u>Where:</u>
Substituting the given parameters into the formula, we have;
z = 0.012/0.0633
z = 0.190.
From the z-table, a z-score of 0.190 is equal to a p-value of 2.37.
For the critical value, we have:
Critical probability (p*) = 1 - α/2
Critical probability (p*) = 1 - 0.1/2
Critical probability (p*) = 0.95.
Hence, the critical value is Zα/2 equal to 1.645.
Since 2.37 is greater than (>) 1.645, we reject the null hypothesis (H₀) at 5% level of significance. Therefore, we can conclude that the company’s claims are invalid.
Read more on null hypothesis here: brainly.com/question/14913351
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