17. Two machine tools, Machine A and Machine B, produce the same type of product. Products are classified by quality into first-grade and second-grade products. To compare the quality of products from the two machines, 200 products were produced by each machine. The quality statistics are shown in the table below:

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\begin{tabular}{ | c | c | c | c | }
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 & First-grade & Second-grade & Total \\
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Machine A & 150 & 50 & 200 \\
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Machine B & 120 & 80 & 200 \\
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Total & 270 & 130 & 400 \\
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\end{tabular}
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(1) What are the frequencies of first-grade products produced by Machine A and Machine B, respectively?\\
(2) Can we conclude with 99\% confidence that there is a difference in product quality between Machine A and Machine B?\\
Attachment: $\mathrm { K } ^ { 2 } = \frac { n ( a d - b c ) ^ { 2 } } { ( a + b ) ( c + d ) ( a + c ) ( b + d ) }$,

\begin{center}
\begin{tabular}{ | c | l | l | c | }
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$\mathrm { P } \left( \mathrm { K } ^ { 2 } \geqslant k \right)$ & 0.050 & 0.010 & 0.001 \\
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$k$ & 3.841 & 6.635 & 10.828 \\
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\end{tabular}
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