Please Help! If (5x-2)^2=ax^2-bx+c, what is the value of a+c^2?

In Melanie's Styling Salon, the time to complete a simple haircut is normally distributed with a mean of 25 minutes and a standa

Triss [41]

Answer:

Longer than 27.7 minutes.

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 25, \sigma = 4$

The slowest quarter of customers will require longer than how many minutes (to the nearest tenth) for a simple haircut?

Longer than the 100 - 25 = 75th percentile of times, which is X when Z has a pvalue of 0.75. So X when Z = 0.675. So

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

$0.675 = \frac{X - 25}{4}$

$X - 25 = 4*0.675$

$X = 27.7$

So

Longer than 27.7 minutes.

8 0

2 years ago

Ramona went to a theme park during spring break. She was there for 7 hours and rode 14 rides. At what rate did Ramona ride rides

Tanzania [10]

Answer:

2 rides per hour

Step-by-step explanation:

This is a division problem since we would need to divide in order to answer the question.

Divide the amount of rides she rode to the number of hours she was there.

Input the numbers below:

amount of rides she rode/number of hours there

14/7=2

At this rate, Ramona rode 2 rides per hour.

8 0

3 years ago

Abdul flips a weighted coin 64 times and gets 16 tails. Based on experimental probability, how many of the next 40 flips should

sergij07 [2.7K]

Answer:

yes, Abdul should expect to come up tails.

7 0

2 years ago

Geometric series plato3ei=1(4x(1/2)i-1)

maw [93]

Answer:

i=1

Step-by-step explanation:

i=(4*(1/2)i-1)

i=2i-1

i=1

4 0

2 years ago

Consider the following hypothesis test. : : The following results are for two independent samples taken from two populations. Ex

I am Lyosha [343]

Answer:

$z = -1.53$ --- test statistic

$p = 0.1260$ --- p value

Conclusion: Fail to reject the null hypothesis.

Step-by-step explanation:

Given

$n_1 = 80$ $\bar x_1= 104$ $\sigma_1 = 8.4$

$n_2 = 70$ $\bar x_2 = 106$ $\sigma_2 = 7.6$

$H_o: \mu_1 - \mu_2 = 0$ --- Null hypothesis

$H_a: \mu_1 - \mu_2 \ne 0$ ---- Alternate hypothesis

$\alpha = 0.05$

Solving (a): The test statistic

This is calculated as:

$z = \frac{\bar x_1 - \bar x_2}{\sqrt{\frac{\sigma_1^2}{n_1} + \frac{\sigma_2^2}{n_2} }}$

So, we have:

$z = \frac{104 - 106}{\sqrt{\frac{8.4^2}{80} + \frac{7.6^2}{70} }}$

$z = \frac{104 - 106}{\sqrt{\frac{70.56}{80} + \frac{57.76}{70}}}$

$z = \frac{-2}{\sqrt{0.8820 + 0.8251}}$

$z = \frac{-2}{\sqrt{1.7071}}$

$z = \frac{-2}{1.3066}$

$z = -1.53$

Solving (b): The p value

This is calculated as:

$p = 2 * P(Z < z)$

So, we have:

$p = 2 * P(Z < -1.53)$

Look up the z probability in the z score table. So, the expression becomes

$p = 2 * 0.0630$

$p = 0.1260$

Solving (c): With $\alpha = 0.05$ , what is the conclusion based on the p value

We have:

$\alpha = 0.05$

In (b), we have:

$p = 0.1260$

By comparison:

$p > \alpha$

i.e.

$0.1260 > 0.05$

So, we fail to reject the null hypothesis.

4 0

2 years ago