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natima [27]
2 years ago
15

Lorelei tosses a coin 4 times. What is the probability of tossing four heads? Express as a percent. Round to the nearest tenth i

f necessary.
Mathematics
1 answer:
Morgarella [4.7K]2 years ago
4 0

Answer:

6.2%

Step-by-step explanation:

For each time the coin is tossed, there are only two possible outcomes. Either it is heads, or it is not. The probability of a toss resulting in heads is independent of other tosses. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

In which C_{n,x} is the number of different combinations of x objects from a set of n elements, given by the following formula.

C_{n,x} = \frac{n!}{x!(n-x)!}

And p is the probability of X happening.

Fair coin:

Equally as likely to be heads or tails, so p = 0.5

Lorelei tosses a coin 4 times.

This means that n = 4.

What is the probability of tossing four heads?

This is P(X = 4).

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

P(X = 4) = C_{4,4}.(0.5)^{4}.(0.5)^{0} = 0.062

0.062 = 6.2% probability of tossing four heads

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Three pounds of squid can be purchased at the market for $18. Determine the equation and represent the function that defines the
olga_2 [115]
From the information given,

3 pounds = $18

Therefore, 1 pound = 18/3 = $6 (this can be treated as a constant of proportionality) such that,

Cost,C = 6*Weight, W (pounds)

Equation;

C = 6W, where C = Cost in $, and W = Weight in pounds.
7 0
2 years ago
Ritu started a business and borrowed a certain sum at 14% per annum for 1 year, the interest being compounded semi annually. If
liubo4ka [24]

Use the formula A = p( 1 + x)^n.

A = 1831.84(1 + 0.14)^6

You can finish.

5 0
2 years ago
A supervisor records the repair cost for 17 randomly selected stereos. A sample mean of $66.34 and standard deviation of $15.22
expeople1 [14]

Answer:

Critical value: T = 1.337

The 80% confidence interval for the mean repair cost for the stereos is between $45.991 and $86.689

Step-by-step explanation:

We have the standard deviation for the sample. So we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 17 - 1 = 16

80% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 16 degrees of freedom(y-axis) and a confidence level of 1 - \frac{1 - 0.8}{2} = 0.9. So we have T = 1.337, which is the critical value

The margin of error is:

M = T*s = 1.337*15.22 = 20.349

In which s is the standard deviation of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 66.34 - 20.349 = $45.991

The upper end of the interval is the sample mean added to M. So it is 66.34 + 20.349 = $86.689

The 80% confidence interval for the mean repair cost for the stereos is between $45.991 and $86.689

3 0
2 years ago
Three erasers and five pencils cost $7.55. 6 erasers and 12 pencils cost $17.40. How much does 1 eraser cost? How much does 1 pe
Sphinxa [80]

Answer:

Step-by-step explanation:

erasers=e  

pencils=p

3e+5p=7.55   ...(1)

6e+12p=17.40

divide by 2

3e+6p=8.70  ...(2)

(2)-(1) gives

p=8.70-7.55=1.15

from (1)

3e+5(1.15)=7.55

3e+5.75=7.55

3e=7.55-5.75

3e=1.80

e=1.80/3=0.60

cost of 1 eraser=$0.60

cost of 1 pencil =$1.15

7 0
2 years ago
Maggie has exactly $20 to buy decorations for the dance. Streamers cost $2 per roll and balloons are $1.50 per package. Which se
IgorC [24]

Answer:

streamers are closest to her budget.

Step-by-step explanation:

because if you want to buy balloons then you would have to buy 13.3 3 is infinite, but if you bought streamers then you would only buy 10.

6 0
2 years ago
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