Question 18 Item 18 The distribution of the number of moths captured per night by a certain moth trap is approximately normal wi
1 answer:
Answer:
Standard deviation 46.3
Step-by-step explanation:
A 28% of the distribution is equivalent to a z score of -0.5828, you can use a z table to find that.
Z score is calculated as follows:
x is the number being evaluated
μ is the mean
σ is the standard deviation
And it is used to calculate how many standard deviations you are from the mean of the sample.
Replacing with the known information you can calculate the standard deviation:
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You can use the fact that both 20% and 15% discounts will be merged to reduce 35% of the price of the book that Jamie buys.
By buying the book on sale and using the coupon, Jamie will save
Option B: $11.55
<h3>How are discounts calculated for the case when its sale and we've got discount coupons too?</h3>
Suppose the sale gives p% off.
And the discount coupon provides q% off.
Then we have total discount applied on the cost of the object bought as
(p+q)%
<h3>How to find the percentage from the total value?</h3>Suppose the value of which a thing is expressed in percentage is "a'
Suppose the percent that considered thing is of "a" is b%
Then since percent shows per 100 (since cent means 100), thus we will first divide the whole part in 100 parts and then we multiply it with b so that we collect b items per 100 items(that is exactly what b per cent means).
Thus, that thing in number is
Since the sale offers 20% discount and Jamie has got 15% discount coupon for any fiction book, thus, total 35% will be discounted if Jamie buys fiction book.
Since the price of the fiction book that Jamie brought is $32.99, thus,
Saved amount = 35% of $32.99 =
Thus,
By buying the book on sale and using the coupon, Jamie will save
Option B: $11.55
<h3 />Learn more about percentage here:
Answer: 0.70
Step-by-step explanation:
Given : The random variable X, representing the number of accidents in a certain intersection in a week, has the following probability distribution:
x 0 1 2 3 4 5
P(X = x) 0.20 0.30 0.20 0.15 0.10 0.05
Using the above probability distribution , the the probability that in a given week there will be at most 3 accidents is given by :_
Hence, the required probability = 0.70