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Zielflug [23.3K]

3 years ago

15

Mega middle school had a valentine dance four fifths of the students plus 7 teachers were there if there was 495 people at the d

ance how many students attend the school

1 answer:

maria [59]3 years ago

6 0

495-7=488
488/4=122
122*5=610

The answer is 610 students attend the school.

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If the average yield of cucumber acre is 800 kg, with a variance 1600 kg, and that the amount of the cucumber follows the normal

lorasvet [3.4K]

Answer:

a

The percentage is

$P(x_1 < X < x_2 ) = 51.1 \%$

b

The probability is $P(Z > 2.5 ) = 0.0062097$

Step-by-step explanation:

From the question we are told that

The population mean is $\mu = 800$

The variance is $var(x) = 1600 \ kg$

The range consider is $x_1 = 778 \ kg \ x_2 = 834 \ kg$

The value consider in second question is $x = 900 \ kg$

Generally the standard deviation is mathematically represented as

$\sigma = \sqrt{var (x)}$

substituting value

$\sigma = \sqrt{1600}$

$\sigma = 40$

The percentage of a cucumber give the crop amount between 778 and 834 kg is mathematically represented as

$P(x_1 < X < x_2 ) = P( \frac{x_1 - \mu }{\sigma} < \frac{X - \mu }{ \sigma } < \frac{x_2 - \mu }{\sigma } )$

Generally $\frac{X - \mu }{ \sigma } = Z (standardized \ value \ of \ X)$

So

$P(x_1 < X < x_2 ) = P( \frac{778 - 800 }{40} < Z< \frac{834 - 800 }{40 } )$

$P(x_1 < X < x_2 ) = P(z_2 < 0.85) - P(z_1 < -0.55)$

From the z-table the value for $P(z_1 < 0.85) = 0.80234$

and $P(z_1 < -0.55) = 0.29116$

So

$P(x_1 < X < x_2 ) = 0.80234 - 0.29116$

$P(x_1 < X < x_2 ) = 0.51118$

The percentage is

$P(x_1 < X < x_2 ) = 51.1 \%$

The probability of cucumber give the crop exceed 900 kg is mathematically represented as

$P(X > x ) = P(\frac{X - \mu }{\sigma } > \frac{x - \mu }{\sigma } )$

substituting values

$P(X > x ) = P( \frac{X - \mu }{\sigma } >\frac{900 - 800 }{40 } )$

$P(X > x ) = P(Z >2.5 )$

From the z-table the value for $P(Z > 2.5 ) = 0.0062097$

7 0

3 years ago

Maria takes guitar lessons that last 4/5 of an hour. She had 4 lessons last week. What is the total number of hours Maria spent

Mazyrski [523]

192 minutes or 3 hours and 12 minutes

an hour is 60 minutes and 60 divided by five is 12 so i multiplied 12 by 4, which is 48 and multiplied 48 by 4 and i got my answer

4 0

2 years ago

Help me with math please

slava [35]

Both of these lines share the relationship together of being parallel.

3 0

3 years ago

American Vending (AV) supplies vended food to a large university. Because students often kick the machines out of anger and frus

aev [14]

Answer:

case 2 with two workers is the optimal decision.

Step-by-step explanation:

Case 1—One worker:A= 3/hour Poisson, ¡x =5/hour exponential The average number of machines in the system isL = - 3. = 4 = lJr machines' ix-A 5 - 3 2 2Downtime cost is $25 X 1.5 = $37.50 per hour; repair cost is $4.00 per hour; and total cost per hour for 1worker is $37.50 + $4.00

= $41.50.Downtime (1.5 X $25) = $37.50 Labor (1 worker X $4) = 4.00

$41.50

Case 2—Two workers: K = 3, pl= 7L= r= = 0.75 machine1 p. -A 7 - 3Downtime (0.75 X $25) = S J 8.75Labor (2 workers X S4.00) = 8.00S26.75Case III—Three workers:A= 3, p= 8L= ——r = 5- ^= § = 0.60 machinepi -A 8 - 3 5Downtime (0.60 X $25) = $15.00 Labor (3 workers X $4) = 12.00 $27.00

Comparing the costs for one, two, three workers, we see that case 2 with two workers is the optimal decision.

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3 years ago

What's the slope of the lines: (-9,5) and (-3,3)

Leokris [45]

The slope of the line is -2/6

4 0

3 years ago