Answer:
Step-by-step explanation:
Amount paid for first 100 watches = (65% of 80) *100
Amount paid for next 50 watches = (55% of 80) * 50
Remaining watches = 280 -(100+ 55)
= 280 - 155 = 125
Amount paid for 125 watches = (45% of 80) *125
Amount received by the watch maker = 5200 + 2200 + 4500
= £ 11900
Answer: 0.05
Step-by-step explanation:
Given : To ensure the quality of the shipment, he selected a random sample of 300 cups and inspected them for defects. He found 15 to be defective.
i.e. sample size : n= 300
sample proportion :
The best estimate for population proportion is the sample proportion.
Therefore, the estimated proportion defective in the population : 0.05
Answer:
Student do better in Chemistry subject.
Step-by-step explanation:
We are given that at a college the scores on the chemistry final exam are approximately normally distributed, with a mean of 77 and a standard deviation of 10. The scores on the calculus final are also approximately normally distributed, with a mean of 83 and a standard deviation of 14.
A student scored 81 on the chemistry final and 81 on the calculus final.
And we have to find that in which subject did the student do better.
<em>Firstly, Let X = scores on the chemistry final exam</em>
<em>So, X ~ N(</em><em>)</em>
<em>Also, let Y = scores on the calculus final exam</em>
<em>So, Y ~ N(</em><em>)</em>
For finding in which subject did the student do better, we will find the z score for both the exams of student because the higher the z score, the better is the student perform in that exam.
The z-score probability distribution is given by;
Z = ~ N(0,1)
where, = mean score for respective subjects
= standard deviation
Since we are given the student score of 81 on the chemistry final exam,
So, z-score = = 0.4 {where
and
}
Since we are given the student score of 81 on the calculus final exam,
So, z-score = = -0.143 {where
and
}
AS we can clearly see that the z score of Chemistry final exam is higher than that of Calculus exam so the student do better in Chemistry subject exam.