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2 years ago

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in the school chorus,2/5 of the students are fourths graders and 1/3 of the students are fifth graders.If there 45 students in c

horus,how many students are either fourth graders or fifth graders?

1 answer:

yulyashka [42]2 years ago

3 0

Answer:

18 students in 4th grade

15 students in 5th grade

Step-by-step explanation:

1/3 of 45 = 15 students in 5th grade

2/5 of 45 = 18 students in 4th grade

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For a field trip 11 students rode in cars and the rest filled eight buses. Which equation below will help you find how many stud

Helen [10]

Answer:

8x + 11= 315

Step-by-step explanation:

Let x = the number of students in a bus

There are 8 buses

8x is the number of students in buses

There are 11 students in cars

Add this together to get all the students, which is 315

8x + 11= 315

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3 years ago

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Can you solve please -8(0.09) (-0.5)=?

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-8(0.09) (-0.5) = 0.36

-8(0.09) (-0.5)

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2 years ago

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Which coordinate pair identifies a point in the third quadrant of the coordinate plane?

Fudgin [204]

Answer:

D, (-6,-2)

Step-by-step explanation:

the first quadrant of a coordinate plane has the x coordinate being a negative number, and the y coordinate being a positive number

the second quadrant of a coordinate plane has the x and y coordinates being a positive number

the third quadrant of a coordinate plane has the x and y coordinates being a negative number

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i have attached a graph showing the quadrants for a visual point of view

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3 years ago

What is the geometric mean of 50 and 1/8

lesya692 [45]

2.5 is the geometric mean

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3 years ago

The width of a casing for a door is normally distributed with a mean of 24 in and a standard deviation of 0.14 in. The width of

Galina-37 [17]

Answer:

0.2296 = 22.96% probability that the width of the casing exceeds the width of the door by more than 0.25 in.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Subtraction of normal variables:

When we subtract normal variables, the mean is the subtraction of the means, while the standard deviation is the square root of the sum of the variances.

The width of a casing for a door is normally distributed with a mean of 24 in and a standard deviation of 0.14 in.

This means that $\mu_{C} = 24, \sigma_{C} = 0.14$

The width of a door is normally distributed with a mean of 23.87 in and a standard deviation of 0.08 in.

This means that $\mu_{D} = 23.87, \sigma_{D} = 0.08$ .

Find the probability that the width of the casing exceeds the width of the door by more than 0.25 in?

This is P(C - D > 0.25).

Distribution C - D:

The mean is:

$\mu = \mu_{C} - \mu_{D} = 24 - 23.87 = 0.13$

The standard deviation is:

$\sigma = \sqrt{\sigma_{C}^2+\sigma_{D}^2} = \sqrt{0.14^2+0.08^2} = 0.1612$

Probability:

This probability is 1 subtracted by the pvalue of Z when X = 0.25. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{0.25 - 0.13}{0.1612}$

$Z = 0.74$

$Z = 0.74$ has a pvalue of 0.7704

1 - 0.7704 = 0.2296

0.2296 = 22.96% probability that the width of the casing exceeds the width of the door by more than 0.25 in.

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3 years ago