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3 years ago

Rebecca throws a fair six sided dice.

Mathematics

1 answer:

NeTakaya3 years ago

5 0

Answer:

Step-by-step explanation: The dice will always land on a number between 1 and 6 because as long as it lands on a number this will come true so there is a 100% chance that a number is landed on. G

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If the price of an object dropped 35% down to 91.00, what was the original price?

densk [106]

260 was its original prize.

8 0

3 years ago

The dual bar chart shows the hair colour of boys and girls in a year group. What fraction of the students are girls? Give your a

Tems11 [23]

Answer:

5/11

Step-by-step explanation:

Black= 22 b+17 g

Brown= 4 b +18 g

Blonde= 25 b+ 10 g

Red= 21 b+ 15 g

Total number= 22+17+4+18+25+10+21+15= 132

Number of girls= 17+18+10+15= 60

Girls are 60/132= 2 × 2 × 3 × 5/ 2 × 2 × 3 × 11= 5/11 of all students

7 0

3 years ago

Billy is playing a game using a bag with 11 marbles inside. The bag contains 3 red, 3 orange, 1 yellow, 2 purple marbles, and 2

Dmitrij [34]

Answer: 3/55

Step-by-step explanation:

From the information given, the bag contains 3 red, 3 orange, 1 yellow, 2 purple marbles, and 2 Pink marbles. Each time he picks an orange marble, she will win a prize.

If he picks a marble the first time, the probability of picking an orange marble will be 3/11. After that we will have 10 marbles left as one has been picked and have 2 orange marbles left, then the probability of picking another orange marble will be 2/10.

Therefore, the probability he will win a prize on both picks will be:

= 3/11 × 2/10

= 6/110

= 3/55

4 0

3 years ago

In a process that manufactures bearings, 90% of the bearings meet a thickness specification. A shipment contains 500 bearings. A

vredina [299]

Answer:

c) P(270≤x≤280)=0.572

d) P(x=280)=0.091

Step-by-step explanation:

The population of bearings have a proportion p=0.90 of satisfactory thickness.

The shipments will be treated as random samples, of size n=500, taken out of the population of bearings.

As the sample size is big, we will model the amount of satisfactory bearings per shipment as a normally distributed variable (if the sample was small, a binomial distirbution would be more precise and appropiate).

The mean of this distribution will be:

$\mu_s=np=500*0.90=450$

The standard deviation will be:

$\sigma_s=\sqrt{np(1-p)}=\sqrt{500*0.90*0.10}=\sqrt{45}=6.7$

We can calculate the probability that a shipment is acceptable (at least 440 bearings meet the specification) calculating the z-score for X=440 and then the probability of this z-score:

$z=(x-\mu_s)/\sigma_s=(440-450)/6.7=-10/6.7=-1.49\\\\P(z>-1.49)=0.932$

Now, we have to create a new sampling distribution for the shipments. The size is n=300 and p=0.932.

The mean of this sampling distribution is:

$\mu=np=300*0.932=279.6$

The standard deviation will be:

$\sigma=\sqrt{np(1-p)}=\sqrt{300*0.932*0.068}=\sqrt{19}=4.36$

c) The probability that between 270 and 280 out of 300 shipments are acceptable can be calculated with the z-score and using the continuity factor, as this is modeled as a continuos variable:

$P(270\leq x\leq280)=P(269.5$

d) The probability that 280 out of 300 shipments are acceptable can be calculated using again the continuity factor correction:

$P(X=280)=P(279.5$

8 0

3 years ago

Katie was selling her necklaces at a garage sale. She sold 4 bead necklaces and 3 gem stone necklaces if each necklace cost $3 h

Mrrafil [7]

Answer: 21

Step-by-step explanation:

4 • 3 = 12

3•3=9

12+9= 21

6 0

3 years ago