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Dorothy can type 120 words per minute. Which can also be represented by
120 x 1 (minute)= 120
If you want to know how many words it takes her for 1.75 minutes, simply multiply 120 by 1.75.
120 x 1.75 (minutes)=210
Answer: 210 words
2y² + y - 3
(2y+3)(y-1)
2y(y-1) + 3(y-1)
2y² - 2y + 3y - 3
2y² + y - 3
2y + 3 = 0
2y = -3
y = -3/2
y = -1 1/2
y - 1 = 0
y = 1
2y² + y - 3 = 0
2(-3/2)² + (-3/2) - 3 = 0
2(9/4) - 3/2 - 3 = 0
18/4 - 3/2 - 3 = 0
18/4 - (3/2 * 2/2) - 3(4/4) = 0
18/4 - 6/4 - 12/4 = 0
(18 - 6 - 12)/4 = 0
(18 -18)/4 = 0
0/4 = 0
0 = 0
Check the picture below
notice, the "a" side goes from -2 to 11
and the "b" side goes from 2 down to -4
Answer:
Step-by-step explanation:
We want to determine a 95% confidence interval for the population mean.
Number of sample, n = 56
Mean, u = 645 hours
Standard deviation, s = 31 hours
For a confidence level of 95%, the corresponding z value is 1.96.
We will apply the formula
Confidence interval
= mean ± z ×standard deviation/√n
It becomes
645 ± 1.96 × 31/√56
= 645 ± 1.96 × 4.142
= 645 ± 8.12
The lower end of the confidence interval is 645 - 8.12 =636.88
The upper end of the confidence interval is 645 + 8.12 =653.12
Therefore, with 95% confidence interval for the population mean life of fluorescent light bulbs is between 636.88 hours and 653.12 hours
