The table shows information about the numbers of hours 30 children spent on their tablets one evening. a) find the class interva
l that contains the median. B)work out an estimate for the mean number of hours
2 answers:
Answer:
a) 20<h≤30.
b) 26.17 hrs
Step-by-step explanation:
The missing table is shown in attachment.
Part a)
We need to find the class interval that contains the median.
The total frequency is
The median class corresponds to half
That is the 15th value.
We start adding the frequency from the top obtain the least cumulative frequency greater or equal to 15.
2+8+9=19
This corresponds to the class interval 20<h≤30.
Adding from the bottom also gives the same result.
Therefore the median class is 20<h≤30.
b) Since this is a grouped data we use the midpoint to represent the class.
The median is given by :
You might be interested in
Answer:
Step-by-step explanation:
we know that
The simple interest formula is equal to
where
I is the Final Interest Value
P is the Principal amount of money to be invested
r is the rate of interest
t is Number of Time Periods
in this problem we have
substitute in the formula above
Solve for t
Convert to percent form
Answer:
B. 10 months
Step-by-step explanation:
The balance on the loan will be ...
b = 1600 - 80t . . . . . . where t is the number of months of payments
The balance in the savings account will be ...
s = 500 + 25t
The savings account balance will be at least as much as the loan balance when ...
s ≥ b
500 +25t ≥ 1600 -80t . . . substitute the account balance expressions
105t ≥ 1100 . . . . . . . . . . . . add 80t -500
t ≥ 1100/105 ≈ 10.48 ≈ 10
It will take Josh 10 months to have enough savings to pay the loan in full.
_____
<em>Comment on rounding</em>
IMO, it makes no sense to round down, as Josh will NOT have enough in 10 months. He will have enough after he makes one more payment of $80. At 10 months, the loan balance is $50 more than the savings balance. It will be 11 months before there is enough savings to pay off the loan.
