Regina’s teacher recently gave her a homework assignment on solving equations. Since she has been thinking about saving for a ne
w cell phone, she decided to use the assignment as an opportunity to model a savings plan.
She created this equation to model the situation. In it, y represents the total amount saved for the new cell phone, 74 is the amount of money she has now, 40 is the amount of money she saves each month for the phone, and x represents the number of months since she started saving a regular amount:
74 + 40x = y.
She then solved the equation to determine how many months she’d need to save to have enough to purchase the new cell phone. Review her work, and select the error.
She created this equation to model the situation. In it, y represents the total amount saved for the new cell phone, 74 is the amount of money she has now, 40 is the amount of money she saves each month for the phone, and x represents the number of months since she started saving a regular amount:
74 + 40x = y.
She then solved the equation to determine how many months she’d need to save to have enough to purchase the new cell phone. Review her work, and select the error.
2 answers:
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Answer:
6000
Step-by-step explanation:
Divide top and bottom by the common factor.
Simplify
3 × 2000 = 6000
Answer:
There is enough evidence to reject the manufacturer’s claim and the standardized test statistic z is -3.43
Step-by-step explanation:
A manufacturer of sprinkler systems designed for fire protection claims that the average activating temperature is at least 135°F.
So, Null hypothesis:
Alternate hypothesis :
To test this claim, you randomly select a sample of 32 systems and find the mean activation temperature to be 133°F.
x=133
n = 32
Population Standard deviation =
Formula :
z=-3.43
Refer the z table for p value
p value = 0.0003
p value < α
So, we failed to accept null hypothesis
Hence there is enough evidence to reject the manufacturer’s claim and the standardized test statistic z is -3.43