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3 years ago

7th grade homework! Probability quick Check Please answer as many as you can/ want to

Mathematics

2 answers:

algol [13]3 years ago

7 0

Number 9 is 36 because there are 18/40 who feel safe, so it multiplied would be 36. C

Travka [436]3 years ago

3 0

There are 5 striped, 6 solid, 2 floral & 2 polka dot t-shirts.

So there are 15 t - shirts in all.

The probability of choosing a polka dot t-shirt is 2/15

The probability of choosing a striped t-shirt is 5/15 = 1/3

Hence the probability of choosing a polka dot t-shirt & then a striped t-shirt = 2/15 × 1/3 = 2/45

Option J) is the right answer

Number of bones = 4

Number of balls = 5

Number of neck belts = 3

Total quantity = 4 + 5 + 3 = 12

The probability of choosing a bone = 4/12 = 1/3

Now as one quantity is selected, the total quantity left now is 11.

The probability of choosing ball is = 5/11

Hence the probability of choosing a bone & then a ball is = 1/3 × 5/11 = 5/33

Option A) is the right answer

Total number of students = 28+14 + 8 = 50

Probability of roller coaster = 28/50 = 14/25

Probability of carnival games =14/50 = 7/25

Probability of Live shows = 8/50 = 4/25

Now 2 times probability of live show = 2(4/25) = 8/25 which is not equal to probability of Roller coaster.

F is not true

As probability of roller coaster ride is more than carnival games.

G is also not true.

Now 2 times the probability of carnival games = 2 (7/25) = 14/25 = Probability of Roller coaster ride.

Hence H is true

Now 2 times the carnival games = 2(7/25) = 14/25 which is not equal to Probability of Carnival games

Hence J is also not true.

Option H) is the true statement.

Here the number of people feeling unsafe is 12, feeling neutral are 10 and feeling safe are 18.

Total number of people is 40.

The probability of a person feeling safe is 12/40

Now for 80 people, the number of people feeling safe shall be 12/40(80) = 24

10)

Here the digits are 1,2,3,4,5,6,7

The digits which are prime are 2,3,5,7

So there are 4 prime digits

The number of non prime digits is 3

And there are 7 digits.

Hence the probability of not selecting a prime number is 3/7

Option F is the right answer.

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Explain how you can tell, without computing, whether the quotient one -half divided into 6 is greater than one or less than one

Helga [31]

If you take 1/2 of a pizza and divide it up between 6 people, will you have more than 1 whole Pizza or less than 1 whole pizza?

If you divide up a fraction into smaller pieces it will always be less than 1 because it started out less than 1 and you're making it even smaller.

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3 years ago

Need a little help with one please

Pani-rosa [81]

Answer:

That would be the side-side-side (SSS) postulate, which states that if all the sides of a triangle are in a fixed ratio to all the corresponding sides of another triangle, then the two triangles are said to be congruent.

Step-by-step explanation:

Looking at triangles ABC and DEF, we notice that:

$\frac{AB}{DE} = \frac{AC}{DF}=\frac{BC}{EF}$

since

$\frac{3}{18} = \frac{6}{36}=\frac{7}{42}=\frac{1}{6}$

Let me know if you have further questions.

4 0

3 years ago

Translate each of the following research questions into appropriate H0 and Ha.

Mandarinka [93]

Answer:

$H_{0}: \mu = 62500\text{ dollars per year}\\H_A: \mu > 62500\text{ dollars per year}$

$H_{0}: \mu = 2.6\text{ hours}\\H_A: \mu \neq 2.6\text{ hours}$

Step-by-step explanation:

We have to build appropriate null and alternate hypothesis for the given scenarios.

a) Population mean, μ = $62,500 per year

The market research wants to find whether the mean household income of mall shoppers is higher than that of the general population.

$H_{0}: \mu = 62500\text{ dollars per year}\\H_A: \mu > 62500\text{ dollars per year}$

We would use one-tail(right) test to perform this hypothesis.

b) Population mean, μ = 2.6 hours

The company want to know the average time to respond to trouble calls is different or not.

$H_{0}: \mu = 2.6\text{ hours}\\H_A: \mu \neq 2.6\text{ hours}$

We would use two-tail test to perform this hypothesis.

7 0

3 years ago

A school staff meeting had 36 teachers in attendance, 75% of whom were first-year teachers. How many first-year teachers were in

natita [175]

Answer:

Step-by-step explanation:

First, lets write this down, 36 x 75%, then lets convert the percent: 36 x .75, multiply! And we get 27.

8 0

3 years ago

Read 2 more answers

In a recent Super Bowl, a TV network predicted that 50 % of the audience would express an interest in seeing one of its forthcom

coldgirl [10]

Answer:

z= -0.968

We can conclude that we fail to reject the null hypothesis, and we can said that at 5% of significance the proportion of people who says that they would watch one of the television shows not differs from 0.5 or 50% .

Step-by-step explanation:

1) Data given and notation n

n=106 represent the random sample taken

X=48 represent the people who says that they would watch one of the television shows.

$\hat p=\frac{48}{106}=0.453$ estimated proportion of people who says that they would watch one of the television shows.

$p_o=0.5$ is the value that we want to test

$\alpha$ represent the significance level

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that 50% of people who says that they would watch one of the television shows.:

Null hypothesis: $p=0.5$

Alternative hypothesis: $p \neq 0.5$

When we conduct a proportion test we need to use the z statisitc, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.453 -0.5}{\sqrt{\frac{0.5(1-0.5)}{106}}}=-0.968$

4) Statistical decision

P value method or p value approach . "This method consists on determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level is not provided, but we can assume $\alpha=0.05$ . The next step would be calculate the p value for this test.

Since is a bilateral test the p value would be:

$p_v =2*P(z$

So based on the p value obtained and using the significance level assumed $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we fail to reject the null hypothesis, and we can said that at 5% of significance the proportion of people who says that they would watch one of the television shows not differs from 0.5 or 50% .

6 0

3 years ago