W / -20 = 2.5 Solve question correctly

Llana has 70¢ in her purse. All the coins have the same value. What could describe all the coins she has in her

sergiy2304 [10]

Answer:

14 nickels

Step-by-step explanation:

One nickel is worth 5 cents, so find the value of 14 nickels by multiplying 14 by 5:

14(5)

= 70

So, 14 nickels is equal to the 70 cents that she has in her purse.

The correct answer is 14 nickels.

6 0

3 years ago

Write an equation to represent the relationship between the step number, n, and the number of dots, y.

KengaRu [80]

The equation that represents the relationship between step number and the number of dots is $y=5^n$ .

Solution:

Let the number of dots be y.

Step number 0: Number of dots = 1

y = 1

Using exponential rule: $a^0=1$

$y=5^0$

Step number 1: Number of dots = 5

y = 5

$y=5^1$

Step number 2: Number of dots = 25

y = 25

$y=5^2$

Step number 3: Number of dots = 125

y = 125

$y=5^3$

Note that in step number 0 the power is 0, 1st step power of 5 is 1, 2nd step power of 5 is 2 and the third step power of 5 is 3.

If the process goes on up to n steps, then power of 5 is n.

∴ Step number n:

$y=5^n$

Number of dots = $5^n$ .

Hence the equation that represents the relationship between step number and the number of dots is $y=5^n$ .

5 0

3 years ago

Help i will vote brainliest answer

mestny [16]

I am not sure
but 90 per cent its option b

7 0

3 years ago

Read 2 more answers

At practice, Joy does twice as many jumping jacks as Bill, and she also does 50 sit-ups. Joy does 112 exercises in total. The eq

olasank [31]

2x + 50 = 112

2x = 112 -50

2x = 62

x = 62:2

x= 31

6 0

3 years ago

A woman is worried that she might have breast cancer. The standard test for breast cancer is mammography. From research she foun

Naddik [55]

Answer:

PPV= 0.432

Step-by-step explanation:

Hello!

Remember:

Any medical test used to detect certain sicknesses have several probabilities associated with their results.

The sensibility of the test is defined as the capacity of the test to detect the sickness in sick patients (true positive rate).

⇒ P(+/S) = P(+ ∩ S)

P(S)

The specificity of the test is the capacity of the test to have a negative result when the patients are truly healthy (true negative rate)

⇒ P(-/H) = P(- ∩ H)

P(H)

Positive predictive value (PPV)

The prevalence of the sickness can be expresed as the probability of being sick in the population of interest.

It's defined as the probability of being sick when the test is positive:

P(S/+)= P(S ∩ +)

P(+)

In this case, the population of interest is "Women in their forties"

The probability of being sick is P(S)= 1 /52= 0.019

The sensibility of this test is P(+/S)= 0.86

The specificity of the test is P(-/H)= 0.97

To calculate the positive predictive value you have to reach the probability of being sick and the test is positive. You can clear this probability using the information of the sensibility of the test and the prevalence of the sickness in the population:

P(+/S) = P(+ ∩ S)

P(S)

P(+ ∩ S) =P(+/S) * P(S) = 0.86*0.019= 0.016

Now you need to calculate the probability of the test being positive P(+)

You can calculate it as: P(+)= P(+ ∩ S) + P(+ ∩ H)

P(+ ∩ H)= P(H) - P(- ∩ H)

The probability of the person being healthy P(H) is complementary to the prevalence of the sickness, symbolically: P(H)= 1 - P(S)= 1 - 0.019= 0.981

Now using the information of the test specificity and the probability of being healthy you can clear P(- ∩ H)

P(- ∩ H)= P(H)*P(-/H) = 0.981*0.97= 0.95157≅0.96

P(+ ∩ H)= P(H) - P(- ∩ H)= 0.981-0.96= 0.021

P(+)= P(+ ∩ S) + P(+ ∩ H)= 0.016+0.021= 0.037

The PPV of the test is:

P(S/+)= P(S ∩ +) = 0.016 = 0.432

P(+) 0.037

I hope it helps!

4 0

3 years ago