Help me out in this question please

Mathematics

1 answer:

stira [4]3 years ago

8 0

Answer:

in this 3 is the correct answer

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Janelle has a babysitting job for the sunumer. She works from 7 AM to 2 P.M. with a 30-minute, unpaid break in the middle of the

shtirl [24]

Answer: $146.25

Step-by-step explanation:

To solve the question, we need to first calculate the number of hours between 7 AM to 2 P.M which is 7 hours but we are told that there is a 30 minutes break. Therefore, he works for 6 hours 30 minutes which is 6 1/2 hours.

She's paid $4.50 pee hour, therefore the amount paid per day will be:

= 6 1/2 × $4.50

= 6.50 × $4.50

= $29.25

The amount that she'll make in 5 days will be:

= $29.25 × 5

= $146.25

7 0

3 years ago

35. In a simple random sample of 25 high school students, the sample mean of the SAT scores was 1450, and the sample variance wa

Tatiana [17]

Answer:

$1450-2.0\frac{30}{\sqrt{25}}=1450-12$

$1450+2.0\frac{30}{\sqrt{25}}=1450+12$

And the best option would be:

c. 1450 +/- 12

Step-by-step explanation:

Information provided

$\bar X=1450$ represent the sample mean for the SAT scores

$\mu$ population mean (variable of interest)

$s^2 = 900$ represent the sample variance given

n=25 represent the sample size

Solution

The confidence interval for the true mean is given by :

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

The sample deviation would be $s=\sqrt{900}= 30$

The degrees of freedom are given by:

$df=n-1=2-25=24$

The Confidence is 0.954 or 95.4%, the value of $\alpha=0.046$ and $\alpha/2 =0.023$ , assuming that we can use the normal distribution in order to find the quantile the critical value would be $z_{\alpha/2} \approx 2.0$