1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
gtnhenbr [62]
3 years ago
13

The average demand for rental skis on winter Saturdays at a particular area is 150 pairs, which has been quite stable over time.

There is variation due to weather conditions and competing areas; the standard deviation is 20 pairs. The demand distribution seems to be roughly normal.
(a) The rental shop stocks 170 pairs of skis. What is the probability that demand will exceed this supply on any winter Saturday?
(b) How many pairs of skis in stock does the shop have to have to make the probability in question (a) less than .01?
Mathematics
1 answer:
pentagon [3]3 years ago
6 0

Answer:

a) 15.87% probability that demand will exceed this supply on any winter Saturday

b) The shop needs to have 197 pairs of skis in stock.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

\mu = 150, \sigma = 20

(a) The rental shop stocks 170 pairs of skis. What is the probability that demand will exceed this supply on any winter Saturday?

This probability is 1 subtracted by the pvalue of Z when X = 150. So

Z = \frac{X - \mu}{\sigma}

Z = \frac{170 - 150}{20}

Z = 1

Z = 1 has a pvalue of 0.8413

1 - 0.8413 = 0.1587

15.87% probability that demand will exceed this supply on any winter Saturday

(b) How many pairs of skis in stock does the shop have to have to make the probability in question (a) less than .01?

This is X when Z has a pvalue of 0.99.

So X when Z = 2.33

Z = \frac{X - \mu}{\sigma}

2.33 = \frac{X - 150}{20}

X - 150 = 2.33*20

X = 196.6

Rounding up, since the number of pairs is a discrete number

The shop needs to have 197 pairs of skis in stock.

You might be interested in
Using a famous spokesperson to promote a certain product is an example of_
butalik [34]

Answer:

An advertisement.

Step-by-step explanation:

It's called a Celebrity Endorsement but it's a subgroup of an Advert.

6 0
3 years ago
The plane that contains points C and T can also be named plane...
Mnenie [13.5K]

Answer:

  A)  CUB

Step-by-step explanation:

Of the suggested planes, only CUB contains both points C and T.

___

<em>Comments on the other answer choices</em>

BED contains point T, but not C

ACE contains point C, but not T

ABE contains neither C nor T

6 0
3 years ago
Evaluate f(x) =3x+8 for x=1
SpyIntel [72]
X= 11
If you plug in 1 for X in the equation, you will get:
 f(x) =3+8
3+8=11
Hope this helps.

5 0
3 years ago
Can anyone help me solve this.I need proper equation..Thanks​
artcher [175]

Answer:

y = 9\sqrt{2}

Step-by-step explanation:

Using the sine ratio in the right triangle and the exact value

sin45° = \frac{1}{\sqrt{2} }

sin45° = \frac{opposite}{hypotenuse} = \frac{9}{y}

Multiply both sides by y

y × sin45° = 9, that is

y × \frac{1}{\sqrt{2} } = 9

Multiply both sides by \sqrt{2}

y = 9\sqrt{2}

3 0
3 years ago
Read 2 more answers
The Town of Hertfordshire clerk knows that 23% of dogs in the town have completed emotional support training. Hertfordshire plan
Nataly_w [17]

Answer:

95.64% probability that under 30% of the dogs are emotional support trained

Step-by-step explanation:

For each dog, there are only two possible outcomes. Either they have completed emotional support training, or they have not. So we use the binomial probability distribution to solve this problem.

However, we are working with samples that are considerably big. So i am going to aproximate this binomial distribution to the normal.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

E(X) = np

The standard deviation of the binomial distribution is:

\sqrt{V(X)} = \sqrt{np(1-p)}

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that \mu = E(X), \sigma = \sqrt{V(X)}.

In this problem, we have that:

\mu = E(X) = np = 100*0.23 = 23

\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{100*0.23*0.77} = 4.21

What is the probability that under 30% of the dogs are emotional support trained?

30% of 100 is 0.3*100 = 30

So this is the pvalue of Z when X = 30.

Z = \frac{X - \mu}{\sigma}

Z = \frac{30 - 23}{4.1}

Z = 1.71

Z = 1.71 has a pvalue of 0.9564.

So there is a 95.64% probability that under 30% of the dogs are emotional support trained

5 0
3 years ago
Other questions:
  • Which of the following could be the ratio of the length of the longer leg of a 30-60-90 triangle to the length of its hypotenuse
    15·2 answers
  • Ben was walking in Manhattan at a constant speed. He went along 5th avenue from 4th to 98th street. At 3:00 he was on 15th stree
    6·1 answer
  • What is the volume of the pyramid shown below?
    9·1 answer
  • What is the slope of a line that is perpendicular to a line whose equation is −2y=3x+7 ?
    12·2 answers
  • NEED HELP IMMEDIATELY. I WILL BRAINLIEST. NEED TO SOLVE FOR X INTERCEPT
    12·1 answer
  • Solve for q<br><br> - 3/4q = 12 <br><br> q = ___
    11·2 answers
  • D<br> В<br> Tр - 319<br> 129<br> 4p +20°<br> С
    7·1 answer
  • What’s the measure of angle X?
    6·1 answer
  • GIVING BRAINIEST IF CORRECT!!<br><br> Factor x^4 - 16 completely
    13·1 answer
  • Which set of ordered pairs does not represent a function?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!