Complete question:
Para ingresar a la Universidad del Chocó se aplica una prueba de razonamiento que consta de 30 preguntas. Por cada respuesta correcta se asignan 5 puntos y por cada incorrecta (o no contestada) se restan 2 puntos. Si un participante obtuvo un puntaje de 94 puntos, ¿cuantas preguntas respondió bien?
Responder:
número de respuestas correctas = 22
Explicación paso a paso:
Dado lo siguiente:
Número total de preguntas = 30
Deje respuestas correctas = y; Respuestas incorrectas = n
Marca otorgada por y = 5
Marca deducida por n = 2
Si el total de preguntas = 30; luego
y + n = 30 - - - - (1)
Puntuación total obtenida = 94; luego
5y - 2n = 94 - - - (2)
De 1),
y + n = 30
y = 30 - n
Sustituya y = 30 - n en equ (2)
5 (30 - n) - 2n = 94
150 - 5n - 2n = 94
150 - 7n = 94
-7n = 94-150
-7n = - 56
n = 56/7
n = 8
Sustituir n = 8 en (1)
y + n = 30
y + 8 = 30
y = 30 - 8
y = 22
y = número de respuestas correctas = 22
n = número de respuestas incorrectas = 8
Answer:
he can expect to lose 0.5$
Step-by-step explanation:
To solve this problem we must calculate the expected value of the game.
If x is a discrete random variable that represents the gain obtained when rolling a dice, then the expected value E is:

When throwing a dice the possible values are:
x: 1→ -$9; 2→ $4; 3→ -$9; 4→ $8; 5→ -$9; 6→ $12
The probability of obtaining any of these numbers is:

The gain when obtaining an even number is twice the number.
The loss to get an odd number is $ 9
So the expected gain is:

Answer:
5F + -9 C= 160 39°F = 3.9
Step-by-step explanation:
A Table showing Freezing Temperatures in degrees with 2 columns and 6 rows. The First row, F, has the entries, negative 13, negative 4, 5, 14, 23. The second column, C, has the entries, negative 25, negative 20, negative 15, negative 10, negative 5.
The table shows temperatures below freezing measured in different units. Complete the equation in standard form to represent the relationship between F, a temperature measured in degrees Fahrenheit, and C, a temperature measured in degrees Celsius.
5F + -9 C = 160
39°F = 3.9°C rounded to the nearest tenth of a degree
Answer:
The number of rainfalls is 
The answer to the second question is no it will not be valid this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the pH reading) from one rainfall will make the experiment invalid.
Step-by-step explanation:
from the question we are told that
The standard deviation is 
The margin of error is 
Given that the confidence level is 95% then we can evaluate the level of significance as



Next we will obtain the critical value of
from the normal distribution table , the value is 
Generally the sample size is mathematically represented as
![n = [\frac{Z_{\frac{\alpha }{2} * \sigma }}{ E} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%20%5B%5Cfrac%7BZ_%7B%5Cfrac%7B%5Calpha%20%7D%7B2%7D%20%2A%20%20%5Csigma%20%7D%7D%7B%20E%7D%20%5D%5E2)
substituting values
![n = [\frac{1.96 * 0.5 }{ 0.1} ]^2](https://tex.z-dn.net/?f=n%20%20%3D%20%20%5B%5Cfrac%7B1.96%20%2A%200.5%20%7D%7B%200.1%7D%20%5D%5E2)

The answer to the second question is no the validity is null this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the pH reading) from one rainfall will make the experiment invalid
Answer:
There cannot be equal errors in both and yellow has fewer errors.
Step-by-step explanation:
we can do paired t test for these two colours

(one tailed test)
df = 9
The data can be tabulated as follows:
Yellow white
5 7
2 6
6 8
7 5
2 9
5 11
3 8
8 3
4 6
9 10
t-Test: Paired Two Sample for Means
Yellow white
Mean 5.1 7.3
Variance 5.877777778 5.788888889
Observations 10 10
Pearson Correlation -0.139051655
Hypothesized Mean Difference 0
df 9
t Stat -1.908439275
P(T<=t) one-tail 0.044341411
t Critical one-tail 1.833112923
P(T<=t) two-tail 0.088682822
t Critical two-tail 2.262157158
Since p value one tailed = 0.0443 and it is <0.05 our significance level, we reject null hypothesis.
There cannot be equal errors in both and yellow has fewer errors.