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2 years ago

Two quantities x and y are connected by the formula y=7-9x.

Mathematics

2 answers:

WINSTONCH [101]2 years ago

8 0

Answer:

a very nice qualification a very nice

quester [9]2 years ago

3 0

Answer:

a. 7

b. 7/9 or 0.778

Step-by-step explanation:

I hope this is right...

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Mr. Hou put students names in a hat and selected file names without looking. What type of sample did he preform?

Anettt [7]

Step-by-step explanation:

The answer is A. The answer is A because the teacher put names in a hat without looking. That narrows down the answer to A and B. Since he didn't do it in a special scientific way the answer is A

8 0

2 years ago

Suppose a population of 250 crickets double in size every 3 months how many crickets will there be after 2 years

Hitman42 [59]

if they double in size every 3 months and there are 12 months in a year, just multiply 250x4=1000 then multiply that by 2. 1000x2=2000

3 0

2 years ago

Exercise 6.12 presents the results of a poll where 48% of 331 Americans who decide to not go to college do so because they canno

tensa zangetsu [6.8K]

<h2>Answer with explanation:</h2>

As per given , we have

$\hat{p}=0.48$ , n=331

Critical value for 90% Confidence interval : $z_{\alpha/2}=1.645$

a) Confidence interval :

$\hat{p}\pm z_{\alpha/2}\sqrt{\dfrac{\hat{p}(1-\hat{p})}{n}}$

$0.48\pm (1.645)\sqrt{\dfrac{0.48(1-0.48)}{331}}\\\\\approx 0.48\pm0.02746\\\\=(0.48-0.02746,\ 0.48+0.02746)\\\\=(0.45254,\ 0.50746)$

Hence, a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot a ord it : $(0.45254,\ 0.50746)$

b) Margin of error : E=1.5%=0.015

Formula for sample size : $n=p(1-p)(\dfrac{z_{\alpha/2}}{E})^2$

For p =0.48 , we have

$n=0.48(1-0.48)(\dfrac{1.645}{0.015})^2=3001.88373333\approx3002$

Hence, the required sample size to survey = 3002

6 0

2 years ago

Model Exponential Growth Question :A sample of bacteria is growing at a continuously compounding rate. The sample triples in 10

Iteru [2.4K]

Answer:

The number of bacteria $B$ after $d$ days is given by

$B = B_0 (3)^{\frac{1}{10} d}$

where $B_0$ is the initial number of bacteria.

Step-by-step explanation:

The number of bacteria $B$ in the sample triples every 10 days, this means after the first 10th day, the number of bacteria is

$B = B_0 *3,$

where $B_0$ is the initial number of bacteria in the sample.

After the 2nd 10th days, the number of bacteria is

$B = (B_0 *3)*3$

after the 3rd day,

$B =( B_0 *3*3)*3$

and so on.

Thus, the formula we get for the number of bacteria after the <em>n</em>th 10-days is

$B = B_0 (3)^n$

where $n$ is is the <em>n</em>th 10-days.

Since, $n$ is 10 days, we have

$d =10n$

$n =\dfrac{1}{10}$

Substituting that into $B = B_0 (3)^n$ , we get:

$\boxed{ B = B_0 (3)^{\frac{1}{10} d}}$

8 0

2 years ago

Of the coffee makers sold in an appliance store, 4.0% have either a faulty switch or a defective cord, 2.5% have a faulty swi

lukranit [14]

Answer: Hence, Probability that a coffee maker will have a defective cord is 0.376=37.6%.

Step-by-step explanation:

Since we have given that

Let A be the event of getting a faulty switch.

Let B be the event of getting a defective cord.

Here, P(A∪B) = 4% = 0.04

P(A∩B) = 0.1% = 0.001

P(A) = 2.5% = 0.025

We need to find P(B):

As we know that

$P(A\cup B)=P(A)+P(B)-P(A\cap B)\\\\0.04=P(A)+0.025-0.001\\\\0.04=P(A)+0.024\\\\P(A)=0.04-0.024=0.376$

Hence, Probability that a coffee maker will have a defective cord is 0.376=37.6%.

6 0

2 years ago