I need help I don't understand this.

What is the value of x? x = What is the perimeter of ΔABC?

Kryger [21]

Answer: find the third value when two values

The perimeter of ΔABC is 13 cm

Step-by-step explanation:

5 0

3 years ago

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The time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a

AlekseyPX

Answer:

The time that the boys need to beat in order to earn a certificate of recognition from the fitness association is 511.264 seconds.

Step-by-step explanation:

We are given that the time for this event for boys in secondary school is known to possess a normal distribution with a mean of 460 seconds and a standard deviation of 40 seconds.

The fitness association wants to recognize the fastest 10% of the boys with certificates of recognition.

Let X = time for this event for boys in secondary school

SO, X ~ Normal( $\mu=460,\sigma^{2} =40^{2}$ )

The z-score probability distribution for normal distribution is given by;

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

where, $\mu$ = mean time = 460 seconds

$\sigma$ = standard deviation = 40 seconds

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) 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.

Now, it is given that the fitness association wants to recognize the fastest 10% of the boys with certificates of recognition, which means;

P(X > x) = 0.10 {where x is the required time which boy need to beat}

P( $\frac{X-\mu}{\sigma}$ > $\frac{x-460}{40}$ ) = 0.10

P(Z > $\frac{x-460}{40}$ ) = 0.10

So, the critical value of x in the z table which represents the top 10% of the area is given as 1.2816, that is;

$\frac{x-460}{40} =1.2816$

${x-460}{} =1.2816\times 40$

$x$ = 460 + 51.264 = 511.264 seconds

Hence, the time that the boys need to beat in order to earn a certificate of recognition from the fitness association is 511.264 seconds.

8 0

3 years ago

With this diagram, what could be the values of c and d?

Sedaia [141]

Answer:

idk maybe

Step-by-step explanation:

7 0

3 years ago

In a manufacturing plant that produces new computers, a 0.15 probability exists that a computer will be defective. if five compu

Sindrei [870]

The probability that all of them will be defective is 0.0000759375

Explanation

The general Binomial Probability formula is....

$P= ^nC_{r}*p^r*(1-p)^n^-^r$ , where p is the probability of success, n is the total number of trials and r is the desired numbers of trials.

Given, the probability that a computer will be defective is 0.15 , so p = 0.15

Five computers are manufactured and we need to find the probability that all of them will be defective. That means, n = 5 and r = 5

Now according to the above formula....

$P= ^5C_{5}*(0.15)^5*(1-0.15)^5^-^5 \\ \\ P= 1*(0.15)^5* (0.85)^0\\ \\ P=(0.15)^5 =0.0000759375$

So, the probability that all of them will be defective is 0.0000759375

7 0

4 years ago

Distributive property of 9*45

Mashutka [201]

9*45
= 9(40 + 5)
= 360 + 45
= 405

answer
Distributive property of 9*45 = 9(40 + 5)

8 0

3 years ago