Answer: d. if we do not know the population standard deviation and must use the sample standard deviation.
Step-by-step explanation:
We use t-distribution is quite similar to distribution of z-score .
The interpretation of t-scores and z-scores are same.
T- distribution is used when the data is not accurately normal and when the population standard deviation is unknown.
In the absence of population standard deviation , we use the standard deviation of the sample.
So , We use a t distribution for inference about a population mean instead of the standard Normal distribution if we do not know the population standard deviation and must use the sample standard deviation.
Hence, the correct option is : d. if we do not know the population standard deviation and must use the sample standard deviation.
In the problem above, let x be the cost of ticket for adults. Based on the description stated by the clerk, each child's ticket costs x - 11.
The total cost of the ticket is $174.45 and may be used to get the value of x. The equation is,
2x + 3(x - 11) = 174.45
Solving x in the equation gives x = 41.49 and x -11 = 30.49. Thus, each adult's ticket cost $41.49 and child's ticket costs $30.49.
Answer:
The cost is $43.2
Step-by-step explanation:
The first thing to do here is to calculate the amount of energy consumed.
From the question, we are told that this is;
Power * Time
From the question, power = 1600 watts
Time = 9 hours
So amount of energy consumed = 1600 watts * 9 hours = 14,400 watts hour
It should be known that energy is measured in Kilowatts hour ; So therefore 14,440 watts hour is 14,440/1000 kwh = 14.4 kwh
Now, the cost per unit of energy is $3.00 per kwh
So the cost of using 14,400 watts hour would be 14.4 * 3 = $43.2
1. 16
2. 7
3. 36
Hope this helps
Answer:
Step-by-step explanation:
Yes i guess
