X Y

What's the factor of 18 and the sum of -9?

Klio2033 [76]

Factor:-6,-3
-6-3= -9

4 0

2 years ago

supervisor records the repair cost for 25 randomly selected dryers. A sample mean of $93.36 and standard deviation of $19.95 are

Simora [160]

<h2><u>Answer with explanation:</u></h2>

The confidence interval for population mean (when population standard deviation is unknown) is given by :-

$\overline{x}-t^*\dfrac{s}{\sqrt{n}}< \mu$

, where n= sample size

$\overline{x}$ = Sample mean

s= sample size

t* = Critical value.

Given : n= 25

Degree of freedom : $df=n-1=24$

$\overline{x}= \$93.36$

$s=\ $19.95$

Significance level for 98% confidence interval : $\alpha=1-0.98=0.02$

Using t-distribution table ,

Two-tailed critical value for 98% confidence interval :

$t^*=t_{\alpha/2,\ df}=t_{0.01,\ 24}=2.4922$

⇒ The critical value that should be used in constructing the confidence interval = 2.4922

Then, the 95% confidence interval would be :-

$93.36-(2.4922)\dfrac{19.95}{\sqrt{25}}< \mu$

$=93.36-9.943878< \mu$

$=83.416122< \mu$

Hence, the 98% confidence interval for the mean repair cost for the dryers. = $83.4161$

4 0

3 years ago

Hector has 3/4 hour to spend his homework. He wants to spend 1/3 of this time on math homework, 10 minutes of his time on readin

DENIUS [597]

Answer:

20 minutes

Step-by-step explanation:

Remember that

$1\ h=60\ mi$

we know that

Hector has 3/4 hour to spend his homework

Convert to minutes

$\frac{3}{4}(60)=45\ min$

so

1) He wants to spend 1/3 of this time on math homework

To find out the time on math homework, multiply 45 minutes by 1/3

$45(\frac{1}{3})=15\ min$

2) He wants to spend 10 minutes of his time on reading homework

3) He wants to spend the remaining time on science homework

The time spend on math homework plus the time spend reading homework, plus the time spend on his science homework must be equal to 45 minutes

Let

x ----> the time spend on his science homework

$15+10+x=45$

Solve for x

$25+x=45\\x=45-25\\x=20\ min$

3 0

3 years ago

Mai runs around a 400 meter track at a constant speed of 250 meters per minute. How many minutes does it take Mai to complete 4

goldfiish [28.3K]

Answer:

6.4 minutes, or 6 minutes and 24 seconds

Step-by-step explanation:

She is running 4 laps, so she is running 1600 meters total. If she runs 250 meters per minute, divide 1600 by 250 to determine how many minutes it will take...

1600/250 = 6.4

Which is 6 minutes + 0.4 minutes

*there are 60 seconds in a minute, so the 0.4 represents 40% of another minute. Multiply 60 by 0.4 to see how many seconds this is...

(0.4)60 = 24 seconds,

So she ran the laps in 6 minutes and 24 seconds

7 0

3 years ago

Read 2 more answers

Which is an equation of the line that goes through the points (-4, -1) and (-2, 3)?

Anna007 [38]

Answer:

The answer is B ...........

3 0

2 years ago