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3 years ago

Students who attend Washington Middle School are either in seventh or eighth grade.

Mathematics

1 answer:

IgorLugansk [536]3 years ago

3 0

Answer:

There are 1240 students at Washington middle school.

Step-by-step explanation:

Percentages and Portions

We can find portions of a whole by correctly managing the percentages of each part. We know 25% of all students at Washington middle school were on the honor roll. From that portion, 60% of the students are seventh graders. That means 40% of the 25% are eight graders, i.e. 40*25%=10% were from eight grade.

We have 10% of all students are 124, thus the number of students are 124/10%=1240

There are 1240 students at Washington middle school.

Let's test the answer. 25% of 1240 students are on the honor roll, which is 310 students. 40% of 310 students are from 8th grade, 40%*310 = 124 as stated in the problem

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Is a triangle whose side measure 12 ft, 16 ft and 20 ft a right triangle?

tensa zangetsu [6.8K]

Answer:

This is a Right Triangle

Step-by-step explanation:

12=a 16=b 20=c

Now lets solve

a^2+b^2=c^2

144+b^2=c^2

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3 years ago

Two points are 17 units apart on a number line. The coordinate of one point is -20.

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Step-by-step explanation:

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4 years ago

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3 years ago

A school baseball team raised $810 for new uniforms.Each player sold 1 book of tickets.There were 10 tickets in a book and each

Leviafan [203]

Answer:

The school baseball team sold 270 tickets

Step-by-step explanation:

Step 1

Identify the total amount of tickets sold by each player;

1 player=1 book of tickets

But 1 book=10 tickets

Step 2

Express the total cost of ticket sales per book as follows;

total cost=cost per ticket×number of tickets per book

where;

cost per ticket=$3

number of tickets per book=10

replacing;

total cost=(3×10)=$30

Step 3

Using the expression below, solve for the number of tickets sold

Total amount raised=price per ticket×number of tickets sold

where;

total amount raised=$810

price per ticket=$3

number of tickets sold=n

replacing;

810=3×n

3 n=810

n=810/3=270

n=270

The school baseball team sold 270 tickets

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3 years ago

Birth weights of babies born to full-term pregnancies follow roughly a Normal distribution. At Meadowbrook Hospital, the mean we

Marina86 [1]

Answer:

Required Probability = 0.1283 .

Step-by-step explanation:

We are given that at Meadow brook Hospital, the mean weight of babies born to full-term pregnancies is 7 lbs with a standard deviation of 14 oz.

Firstly, standard deviation in lbs = 14 ÷ 16 = 0.875 lbs.

Also, Birth weights of babies born to full-term pregnancies follow roughly a Normal distribution.

Let X = mean weight of the babies, so X ~ N( $\mu = 7 lbs , \sigma^{2} = 0.875^{2} lbs$ )

The standard normal z distribution is given by;

Z = $\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, X bar = sample mean weight

n = sample size = 4

Now, probability that the average weight of the four babies will be more than 7.5 lbs = P(X bar > 7.5 lbs)

P(X bar > 7.5) = P( $\frac{Xbar-\mu}{\frac{\sigma}{\sqrt{n} } }$ > $\frac{7.5-7}{\frac{0.875}{\sqrt{4} } }$ ) = P(Z > 1.1428) = 0.1283 (using z% table)

Therefore, the probability that the average weight of the four babies will be more than 7.5 lbs is 0.1283 .

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4 years ago